12965856921 has 16 divisors (see below), whose sum is σ = 19398865920. Its totient is φ = 8558319600.

The previous prime is 12965856901. The next prime is 12965856923.

12965856921 is a `hidden beast` number, since 1 + 2 + 9 + 6 + 58 + 569 + 21 = 666.

12965856921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 12965856921 - 2⁵ = 12965856889 is a prime.

It is a super-2 number, since 2×12965856921² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (12965856923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2374585 + ... + 2380038.

It is an arithmetic number, because the mean of its divisors is an integer number (1212429120).

Almost surely, 2^12965856921 is an apocalyptic number.

It is an amenable number.

12965856921 is a deficient number, since it is larger than the sum of its proper divisors (6433008999).

12965856921 is a wasteful number, since it uses less digits than its factorization.

12965856921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4754733 (or 4754727 counting only the distinct ones).

The product of its digits is 2332800, while the sum is 54.

The spelling of 12965856921 in words is "twelve billion, nine hundred sixty-five million, eight hundred fifty-six thousand, nine hundred twenty-one".