18021173564 has 12 divisors (see below), whose sum is σ = 31578069600. Its totient is φ = 8998867968.

The previous prime is 18021173557. The next prime is 18021173567. The reversal of 18021173564 is 46537112081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18021173567) 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, 2926244 + ... + 2932395.

It is an arithmetic number, because the mean of its divisors is an integer number (2631505800).

Almost surely, 2^18021173564 is an apocalyptic number.

It is an amenable number.

18021173564 is a deficient number, since it is larger than the sum of its proper divisors (13556896036).

18021173564 is a wasteful number, since it uses less digits than its factorization.

18021173564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5859412 (or 5859410 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 38.

The spelling of 18021173564 in words is "eighteen billion, twenty-one million, one hundred seventy-three thousand, five hundred sixty-four".