12691655 has 4 divisors (see below), whose sum is σ = 15229992. Its totient is φ = 10153320.

The previous prime is 12691649. The next prime is 12691691. The reversal of 12691655 is 55619621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55619621 = 37 ⋅1503233.

It is not a de Polignac number, because 12691655 - 2¹⁸ = 12429511 is a prime.

It is a super-2 number, since 2×12691655² = 322156213278050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 1269161 + ... + 1269170.

It is an arithmetic number, because the mean of its divisors is an integer number (3807498).

Almost surely, 2^12691655 is an apocalyptic number.

12691655 is a deficient number, since it is larger than the sum of its proper divisors (2538337).

12691655 is an equidigital number, since it uses as much as digits as its factorization.

12691655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2538336.

The product of its digits is 16200, while the sum is 35.

The square root of 12691655 is about 3562.5349121096. The cubic root of 12691655 is about 233.2595424260.

The spelling of 12691655 in words is "twelve million, six hundred ninety-one thousand, six hundred fifty-five".