12651665 has 16 divisors (see below), whose sum is σ = 16632000. Its totient is φ = 9181632.

The previous prime is 12651659. The next prime is 12651697. The reversal of 12651665 is 56615621.

It is a cyclic number.

It is not a de Polignac number, because 12651665 - 2¹⁴ = 12635281 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2186 + ... + 5484.

It is an arithmetic number, because the mean of its divisors is an integer number (1039500).

Almost surely, 2^12651665 is an apocalyptic number.

It is an amenable number.

12651665 is a deficient number, since it is larger than the sum of its proper divisors (3980335).

12651665 is a wasteful number, since it uses less digits than its factorization.

12651665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3376.

The product of its digits is 10800, while the sum is 32.

The square root of 12651665 is about 3556.9179074024. The cubic root of 12651665 is about 233.0142929949.

It can be divided in two parts, 126516 and 65, that multiplied together give a triangular number (8223540 = T₄₀₅₅).

The spelling of 12651665 in words is "twelve million, six hundred fifty-one thousand, six hundred sixty-five".