11979391656961 has 4 divisors (see below), whose sum is σ = 12001291825072. Its totient is φ = 11957491488852.

The previous prime is 11979391656931. The next prime is 11979391656989. The reversal of 11979391656961 is 16965619397911.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11979391656961 - 2²³ = 11979383268353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11979391656931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10950083235 + ... + 10950084328.

It is an arithmetic number, because the mean of its divisors is an integer number (3000322956268).

Almost surely, 2^{11979391656961} is an apocalyptic number.

It is an amenable number.

11979391656961 is a deficient number, since it is larger than the sum of its proper divisors (21900168111).

11979391656961 is an equidigital number, since it uses as much as digits as its factorization.

11979391656961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21900168110.

The product of its digits is 148803480, while the sum is 73.

The spelling of 11979391656961 in words is "eleven trillion, nine hundred seventy-nine billion, three hundred ninety-one million, six hundred fifty-six thousand, nine hundred sixty-one".