12911665 has 8 divisors (see below), whose sum is σ = 16685928. Its totient is φ = 9534720.

The previous prime is 12911651. The next prime is 12911683. The reversal of 12911665 is 56611921.

It can be written as a sum of positive squares in 4 ways, for example, as 1595169 + 11316496 = 1263^2 + 3364^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12911665 - 2¹⁹ = 12387377 is a prime.

It is a super-2 number, since 2×12911665² = 333422186144450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99256 + ... + 99385.

It is an arithmetic number, because the mean of its divisors is an integer number (2085741).

Almost surely, 2^12911665 is an apocalyptic number.

It is an amenable number.

12911665 is a deficient number, since it is larger than the sum of its proper divisors (3774263).

12911665 is a wasteful number, since it uses less digits than its factorization.

12911665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198659.

The product of its digits is 3240, while the sum is 31.

The square root of 12911665 is about 3593.2805345533. The cubic root of 12911665 is about 234.5996806032.

The spelling of 12911665 in words is "twelve million, nine hundred eleven thousand, six hundred sixty-five".