21303731540 has 96 divisors (see below), whose sum is σ = 55370407680. Its totient is φ = 6704510976.

The previous prime is 21303731483. The next prime is 21303731563. The reversal of 21303731540 is 4513730312.

It is a congruent number.

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, 293084 + ... + 358476.

It is an arithmetic number, because the mean of its divisors is an integer number (576775080).

Almost surely, 2^21303731540 is an apocalyptic number.

21303731540 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 21303731540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27685203840).

21303731540 is an abundant number, since it is smaller than the sum of its proper divisors (34066676140).

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

21303731540 is a wasteful number, since it uses less digits than its factorization.

21303731540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65601 (or 65599 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 29.

The spelling of 21303731540 in words is "twenty-one billion, three hundred three million, seven hundred thirty-one thousand, five hundred forty".