12691057 has 2 divisors, whose sum is σ = 12691058. Its totient is φ = 12691056.

The previous prime is 12691043. The next prime is 12691079. The reversal of 12691057 is 75019621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11861136 + 829921 = 3444^2 + 911^2 .

It is a cyclic number.

It is not a de Polignac number, because 12691057 - 2⁷ = 12690929 is a prime.

It is a super-2 number, since 2×12691057² = 322125855554498, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12691087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6345528 + 6345529.

It is an arithmetic number, because the mean of its divisors is an integer number (6345529).

Almost surely, 2^12691057 is an apocalyptic number.

It is an amenable number.

12691057 is a deficient number, since it is larger than the sum of its proper divisors (1).

12691057 is an equidigital number, since it uses as much as digits as its factorization.

12691057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 12691057 is about 3562.4509821189. The cubic root of 12691057 is about 233.2558788271.

The spelling of 12691057 in words is "twelve million, six hundred ninety-one thousand, fifty-seven".