18973561979155 has 12 divisors (see below), whose sum is σ = 26485543661040. Its totient is φ = 13010442499824.

The previous prime is 18973561979147. The next prime is 18973561979167. The reversal of 18973561979155 is 55197916537981.

It is not a de Polignac number, because 18973561979155 - 2³ = 18973561979147 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38721554815 + ... + 38721555304.

It is an arithmetic number, because the mean of its divisors is an integer number (2207128638420).

Almost surely, 2^{18973561979155} is an apocalyptic number.

18973561979155 is a deficient number, since it is larger than the sum of its proper divisors (7511981681885).

18973561979155 is an equidigital number, since it uses as much as digits as its factorization.

18973561979155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77443110138 (or 77443110131 counting only the distinct ones).

The product of its digits is 642978000, while the sum is 76.

The spelling of 18973561979155 in words is "eighteen trillion, nine hundred seventy-three billion, five hundred sixty-one million, nine hundred seventy-nine thousand, one hundred fifty-five".