12691967 has 4 divisors (see below), whose sum is σ = 12699240. Its totient is φ = 12684696.

The previous prime is 12691957. The next prime is 12691997. The reversal of 12691967 is 76919621.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 76919621 = 2531 ⋅30391.

It is a cyclic number.

It is not a de Polignac number, because 12691967 - 2⁸ = 12691711 is a prime.

It is a super-2 number, since 2×12691967² = 322172052658178, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12691907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 728 + ... + 5090.

It is an arithmetic number, because the mean of its divisors is an integer number (3174810).

Almost surely, 2^12691967 is an apocalyptic number.

12691967 is the 2909-th pentagonal number.

12691967 is a deficient number, since it is larger than the sum of its proper divisors (7273).

12691967 is an equidigital number, since it uses as much as digits as its factorization.

12691967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7272.

The product of its digits is 40824, while the sum is 41.

The square root of 12691967 is about 3562.5787008851. The cubic root of 12691967 is about 233.2614538231.

The spelling of 12691967 in words is "twelve million, six hundred ninety-one thousand, nine hundred sixty-seven".