18021978363996 has 24 divisors (see below), whose sum is σ = 46723647610640. Its totient is φ = 6007326121296.

The previous prime is 18021978363973. The next prime is 18021978364009. The reversal of 18021978363996 is 69936387912081.

18021978363996 is a `hidden beast` number, since 18 + 0 + 2 + 197 + 8 + 36 + 399 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83435084911 + ... + 83435085126.

Almost surely, 2^{18021978363996} is an apocalyptic number.

It is an amenable number.

18021978363996 is an abundant number, since it is smaller than the sum of its proper divisors (28701669246644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18021978363996 is a wasteful number, since it uses less digits than its factorization.

18021978363996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166870170050 (or 166870170042 counting only the distinct ones).

The product of its (nonzero) digits is 211631616, while the sum is 72.

The spelling of 18021978363996 in words is "eighteen trillion, twenty-one billion, nine hundred seventy-eight million, three hundred sixty-three thousand, nine hundred ninety-six".