21989052500 has 30 divisors (see below), whose sum is σ = 48085665474. Its totient is φ = 8795620000.

The previous prime is 21989052487. The next prime is 21989052517. The reversal of 21989052500 is 525098912.

It can be written as a sum of positive squares in 5 ways, for example, as 14746702096 + 7242350404 = 121436^2 + 85102^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4395311 + ... + 4400310.

Almost surely, 2^21989052500 is an apocalyptic number.

21989052500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21989052500 is an abundant number, since it is smaller than the sum of its proper divisors (26096612974).

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

21989052500 is an equidigital number, since it uses as much as digits as its factorization.

21989052500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8795645 (or 8795628 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 41.

The spelling of 21989052500 in words is "twenty-one billion, nine hundred eighty-nine million, fifty-two thousand, five hundred".