21753118640 has 160 divisors (see below), whose sum is σ = 56935498752. Its totient is φ = 7724640000.

The previous prime is 21753118637. The next prime is 21753118691. The reversal of 21753118640 is 4681135712.

It is a junction number, because it is equal to n+sod(n) for n = 21753118594 and 21753118603.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4576265 + ... + 4581015.

Almost surely, 2^21753118640 is an apocalyptic number.

21753118640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21753118640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28467749376).

21753118640 is an abundant number, since it is smaller than the sum of its proper divisors (35182380112).

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

21753118640 is a wasteful number, since it uses less digits than its factorization.

21753118640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4840 (or 4812 counting only the distinct ones).

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

The spelling of 21753118640 in words is "twenty-one billion, seven hundred fifty-three million, one hundred eighteen thousand, six hundred forty".