21753537237440 has 56 divisors (see below), whose sum is σ = 51855659734752. Its totient is φ = 8692167787520.

The previous prime is 21753537237431. The next prime is 21753537237511. The reversal of 21753537237440 is 4473273535712.

It is a hoax number, since the sum of its digits (53) coincides with the sum of the digits of its distinct prime factors.

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, 35819924 + ... + 36422163.

Almost surely, 2^{21753537237440} is an apocalyptic number.

21753537237440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21753537237440 is an abundant number, since it is smaller than the sum of its proper divisors (30102122497312).

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

21753537237440 is an equidigital number, since it uses as much as digits as its factorization.

21753537237440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72243045 (or 72243035 counting only the distinct ones).

The product of its (nonzero) digits is 14817600, while the sum is 53.

The spelling of 21753537237440 in words is "twenty-one trillion, seven hundred fifty-three billion, five hundred thirty-seven million, two hundred thirty-seven thousand, four hundred forty".