21050500320 has 240 divisors, whose sum is σ = 75340365408. Its totient is φ = 5534161920.

The previous prime is 21050500301. The next prime is 21050500357. The reversal of 21050500320 is 2300505012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21050500293 and 21050500302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 908722 + ... + 931598.

Almost surely, 2^21050500320 is an apocalyptic number.

21050500320 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 21050500320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37670182704).

21050500320 is an abundant number, since it is smaller than the sum of its proper divisors (54289865088).

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

21050500320 is a wasteful number, since it uses less digits than its factorization.

21050500320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22975 (or 22958 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The spelling of 21050500320 in words is "twenty-one billion, fifty million, five hundred thousand, three hundred twenty".