18811372808 has 8 divisors (see below), whose sum is σ = 35271324030. Its totient is φ = 9405686400.

The previous prime is 18811372781. The next prime is 18811372843. The reversal of 18811372808 is 80827311881.

It can be written as a sum of positive squares in only one way, i.e., 18790378084 + 20994724 = 137078^2 + 4582^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1175710793 + ... + 1175710808.

Almost surely, 2^18811372808 is an apocalyptic number.

It is an amenable number.

18811372808 is a deficient number, since it is larger than the sum of its proper divisors (16459951222).

18811372808 is a wasteful number, since it uses less digits than its factorization.

18811372808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2351421607 (or 2351421603 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 47.

The spelling of 18811372808 in words is "eighteen billion, eight hundred eleven million, three hundred seventy-two thousand, eight hundred eight".