12013772955921 has 135 divisors (see below), whose sum is σ = 19942189254603. Its totient is φ = 7202255654880.

The previous prime is 12013772955881. The next prime is 12013772955941. The reversal of 12013772955921 is 12955927731021.

The square root of 12013772955921 is 3466089.

It is a perfect power (a square), and thus also a powerful number.

12013772955921 is a `hidden beast` number, since 1 + 2 + 0 + 13 + 7 + 72 + 9 + 559 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3521421137025 + 8492351818896 = 1876545^2 + 2914164^2 .

It is not a de Polignac number, because 12013772955921 - 2³⁵ = 11979413217553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12013772955941) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 53873421216 + ... + 53873421438.

Almost surely, 2^{12013772955921} is an apocalyptic number.

12013772955921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12013772955921 is the 3466089-th square number.

12013772955921 is the 1733045-th centered octagonal number.

It is an amenable number.

12013772955921 is a deficient number, since it is larger than the sum of its proper divisors (7928416298682).

12013772955921 is an frugal number, since it uses more digits than its factorization.

12013772955921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794 (or 394 counting only the distinct ones).

The product of its (nonzero) digits is 2381400, while the sum is 54.

The spelling of 12013772955921 in words is "twelve trillion, thirteen billion, seven hundred seventy-two million, nine hundred fifty-five thousand, nine hundred twenty-one".