18537811440 has 80 divisors (see below), whose sum is σ = 58689957888. Its totient is φ = 4838234368.

The previous prime is 18537811417. The next prime is 18537811459. The reversal of 18537811440 is 4411873581.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 18537811392 and 18537811401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 810432 + ... + 832991.

Almost surely, 2^18537811440 is an apocalyptic number.

18537811440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18537811440 is an abundant number, since it is smaller than the sum of its proper divisors (40152146448).

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

18537811440 is a wasteful number, since it uses less digits than its factorization.

18537811440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643486 (or 1643480 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 42.

The spelling of 18537811440 in words is "eighteen billion, five hundred thirty-seven million, eight hundred eleven thousand, four hundred forty".