12691 has 8 divisors (see below), whose sum is σ = 15200.
Its totient is φ = 10584.
The previous prime is 12689. The next prime is 12697. The reversal of 12691 is 19621.
It can be divided in two parts, 12 and 691, that added together give a triangular number (703 = T37).
12691 = 183 + 193.
12691 is nontrivially palindromic in base 4 and base 6.
12691 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.
It is not a de Polignac number, because 12691 - 21 = 12689 is a prime.
It is a super-2 number, since 2×126912 = 322122962, which contains 22 as substring.
It is a Duffinian number.
It is a nialpdrome in base 7.
It is not an unprimeable number, because it can be changed into a prime (12697) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 325 + ... + 361.
It is an arithmetic number, because the mean of its divisors is an integer number (1900).
212691 is an apocalyptic number.
12691 is a deficient number, since it is larger than the sum of its proper divisors (2509).
12691 is an frugal number, since it uses more digits than its factorization.
12691 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 58 (or 44 counting only the distinct ones).
The product of its digits is 108, while the sum is 19.
The square root of 12691 is about 112.6543385760.
The cubic root of 12691 is about 23.3255529615.
The spelling of 12691 in words is "twelve thousand, six hundred ninety-one".