21261444152 has 16 divisors (see below), whose sum is σ = 42931762440. Its totient is φ = 9812974176.

The previous prime is 21261444131. The next prime is 21261444161. The reversal of 21261444152 is 25144416212.

It is a super-2 number, since 2×21261444152² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102218378 + ... + 102218585.

Almost surely, 2^21261444152 is an apocalyptic number.

It is an amenable number.

21261444152 is an abundant number, since it is smaller than the sum of its proper divisors (21670318288).

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

21261444152 is a wasteful number, since it uses less digits than its factorization.

21261444152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204436982 (or 204436978 counting only the distinct ones).

The product of its digits is 15360, while the sum is 32.

The spelling of 21261444152 in words is "twenty-one billion, two hundred sixty-one million, four hundred forty-four thousand, one hundred fifty-two".