18645716872 has 32 divisors (see below), whose sum is σ = 35524087200. Its totient is φ = 9173816064.

The previous prime is 18645716783. The next prime is 18645716879. The reversal of 18645716872 is 27861754681.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (18645716879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51463 + ... + 199849.

It is an arithmetic number, because the mean of its divisors is an integer number (1110127725).

Almost surely, 2^18645716872 is an apocalyptic number.

It is an amenable number.

18645716872 is a deficient number, since it is larger than the sum of its proper divisors (16878370328).

18645716872 is a wasteful number, since it uses less digits than its factorization.

18645716872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148645 (or 148641 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 55.

The spelling of 18645716872 in words is "eighteen billion, six hundred forty-five million, seven hundred sixteen thousand, eight hundred seventy-two".