21715246220 has 48 divisors (see below), whose sum is σ = 47605440960. Its totient is φ = 8304823296.

The previous prime is 21715246193. The next prime is 21715246237. The reversal of 21715246220 is 2264251712.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1202216 + ... + 1220144.

It is an arithmetic number, because the mean of its divisors is an integer number (991780020).

Almost surely, 2^21715246220 is an apocalyptic number.

21715246220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21715246220 is an abundant number, since it is smaller than the sum of its proper divisors (25890194740).

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

21715246220 is a wasteful number, since it uses less digits than its factorization.

21715246220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20594 (or 20592 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

Adding to 21715246220 its reverse (2264251712), we get a palindrome (23979497932).

The spelling of 21715246220 in words is "twenty-one billion, seven hundred fifteen million, two hundred forty-six thousand, two hundred twenty".