21249518520720 has 160 divisors (see below), whose sum is σ = 76820417107200. Its totient is φ = 4857032785920.

The previous prime is 21249518520709. The next prime is 21249518520733. The reversal of 21249518520720 is 2702581594212.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21249518520720.

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, 128984241 + ... + 129148880.

It is an arithmetic number, because the mean of its divisors is an integer number (480127606920).

Almost surely, 2^{21249518520720} is an apocalyptic number.

21249518520720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21249518520720 is an abundant number, since it is smaller than the sum of its proper divisors (55570898586480).

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

21249518520720 is a wasteful number, since it uses less digits than its factorization.

21249518520720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258133158 (or 258133138 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 48.

The spelling of 21249518520720 in words is "twenty-one trillion, two hundred forty-nine billion, five hundred eighteen million, five hundred twenty thousand, seven hundred twenty".