12956177081961 has 15 divisors (see below), whose sum is σ = 19354337614183. Its totient is φ = 8637429791160.

The previous prime is 12956177081891. The next prime is 12956177082001. The reversal of 12956177081961 is 16918077165921.

The square root of 12956177081961 is 3599469.

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

12956177081961 is a `hidden beast` number, since 1 + 2 + 9 + 5 + 617 + 7 + 0 + 8 + 1 + 9 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3705698150361 + 9250478931600 = 1925019^2 + 3041460^2 .

It is not a de Polignac number, because 12956177081961 - 2¹⁹ = 12956176557673 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12956177081261) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 32195251 + ... + 32595191.

Almost surely, 2^{12956177081961} is an apocalyptic number.

12956177081961 is the 3599469-th square number.

12956177081961 is the 1799735-th centered octagonal number.

It is an amenable number.

12956177081961 is a deficient number, since it is larger than the sum of its proper divisors (6398160532222).

12956177081961 is an frugal number, since it uses more digits than its factorization.

12956177081961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799894 (or 399944 counting only the distinct ones).

The product of its (nonzero) digits is 11430720, while the sum is 63.

The spelling of 12956177081961 in words is "twelve trillion, nine hundred fifty-six billion, one hundred seventy-seven million, eighty-one thousand, nine hundred sixty-one".