12691831 has 2 divisors, whose sum is σ = 12691832. Its totient is φ = 12691830.

The previous prime is 12691823. The next prime is 12691849. The reversal of 12691831 is 13819621.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12691831 - 2³ = 12691823 is a prime.

It is a super-2 number, since 2×12691831² = 322165148265122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12691793 and 12691802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12691871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6345915 + 6345916.

It is an arithmetic number, because the mean of its divisors is an integer number (6345916).

Almost surely, 2^12691831 is an apocalyptic number.

12691831 is a deficient number, since it is larger than the sum of its proper divisors (1).

12691831 is an equidigital number, since it uses as much as digits as its factorization.

12691831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 31.

The square root of 12691831 is about 3562.5596135363. The cubic root of 12691831 is about 233.2606206539.

The spelling of 12691831 in words is "twelve million, six hundred ninety-one thousand, eight hundred thirty-one".