18193975440 has 40 divisors (see below), whose sum is σ = 56401324608. Its totient is φ = 4851726720.

The previous prime is 18193975391. The next prime is 18193975537. The reversal of 18193975440 is 4457939181.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×18193975440² (a number of 21 digits) contains 22 as substring.

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, 37903876 + ... + 37904355.

Almost surely, 2^18193975440 is an apocalyptic number.

18193975440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18193975440 is an abundant number, since it is smaller than the sum of its proper divisors (38207349168).

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

18193975440 is a wasteful number, since it uses less digits than its factorization.

18193975440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75808247 (or 75808241 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 51.

The spelling of 18193975440 in words is "eighteen billion, one hundred ninety-three million, nine hundred seventy-five thousand, four hundred forty".