21850338520 has 32 divisors (see below), whose sum is σ = 49516966800. Its totient is φ = 8677254528.

The previous prime is 21850338511. The next prime is 21850338533. The reversal of 21850338520 is 2583305812.

It is a self number, because there is not a number n which added to its sum of digits gives 21850338520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1959399 + ... + 1970518.

Almost surely, 2^21850338520 is an apocalyptic number.

21850338520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21850338520 is an abundant number, since it is smaller than the sum of its proper divisors (27666628280).

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

21850338520 is a wasteful number, since it uses less digits than its factorization.

21850338520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3930067 (or 3930063 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 37.

The spelling of 21850338520 in words is "twenty-one billion, eight hundred fifty million, three hundred thirty-eight thousand, five hundred twenty".