21352615320 has 128 divisors (see below), whose sum is σ = 66675052800. Its totient is φ = 5463811584.

The previous prime is 21352615309. The next prime is 21352615343. The reversal of 21352615320 is 2351625312.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 548419 + ... + 586061.

It is an arithmetic number, because the mean of its divisors is an integer number (520898850).

Almost surely, 2^21352615320 is an apocalyptic number.

21352615320 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 21352615320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33337526400).

21352615320 is an abundant number, since it is smaller than the sum of its proper divisors (45322437480).

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

21352615320 is a wasteful number, since it uses less digits than its factorization.

21352615320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37849 (or 37845 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 30.

The spelling of 21352615320 in words is "twenty-one billion, three hundred fifty-two million, six hundred fifteen thousand, three hundred twenty".