second
/ˈsɛkənd/
Binary Representation
11-bit index: 11000010011 (decimal 1555)
Position
#1556 of 2048
Hex Index
0x613
4-Letter Prefix
seco
About "second" in BIP39
"second" is the #1556 word
in the official BIP39 English mnemonic wordlist. It is encoded as the 11-bit binary value
11000010011
(decimal index 1555), placing it at the 76% mark of the full 2048-word list.
The 4-letter prefix "seco" uniquely identifies this word among all 2048 entries. At 6 characters, it falls in the typical length range for BIP39 words, balancing readability with distinctiveness during manual wallet recovery.
Near the end of the wordlist (index 1555), "second" is part of the "S" letter group with 250 entries total, positioned at #39 in that group. Words in the upper range of the list have binary representations with more leading 1s.
In a 12-word seed phrase, each word encodes 11 bits of entropy. The probability of "second" appearing in any specific position of a randomly generated phrase is 1 in 2048 (≈ 0.049%). A complete 24-word phrase encodes 256 bits of entropy, providing security equivalent to a key space of approximately 1.16 × 10⁷⁷ — far beyond the reach of brute-force attacks.
Word #1556 in the Other 9 BIP39 Wordlists
Every official BIP39 wordlist has exactly 2048 entries, so index 1555 encodes the same 11-bit value
(11000010011) in every language.
A wallet configured for one of these languages would use this word instead of "second":