21431598720 has 1024 divisors, whose sum is σ = 88833024000. Its totient is φ = 4282122240.

The previous prime is 21431598707. The next prime is 21431598737. The reversal of 21431598720 is 2789513412.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 240804436 + ... + 240804524.

It is an arithmetic number, because the mean of its divisors is an integer number (86751000).

Almost surely, 2^21431598720 is an apocalyptic number.

21431598720 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 21431598720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44416512000).

21431598720 is an abundant number, since it is smaller than the sum of its proper divisors (67401425280).

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

21431598720 is a wasteful number, since it uses less digits than its factorization.

21431598720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 189 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The spelling of 21431598720 in words is "twenty-one billion, four hundred thirty-one million, five hundred ninety-eight thousand, seven hundred twenty".