21421610252 has 24 divisors (see below), whose sum is σ = 42951160224. Its totient is φ = 9157560192.

The previous prime is 21421610239. The next prime is 21421610263. The reversal of 21421610252 is 25201612412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 952433 + ... + 974664.

It is an arithmetic number, because the mean of its divisors is an integer number (1789631676).

Almost surely, 2^21421610252 is an apocalyptic number.

It is an amenable number.

21421610252 is an abundant number, since it is smaller than the sum of its proper divisors (21529549972).

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

21421610252 is a wasteful number, since it uses less digits than its factorization.

21421610252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1927505 (or 1927503 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The spelling of 21421610252 in words is "twenty-one billion, four hundred twenty-one million, six hundred ten thousand, two hundred fifty-two".