21242531328 has 40 divisors (see below), whose sum is σ = 56591435208. Its totient is φ = 7080843264.

The previous prime is 21242531327. The next prime is 21242531329. The reversal of 21242531328 is 82313524212.

It is an interprime number because it is at equal distance from previous prime (21242531327) and next prime (21242531329).

It is a super-2 number, since 2×21242531328² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242531327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6913351 + ... + 6916422.

Almost surely, 2^21242531328 is an apocalyptic number.

It is an amenable number.

21242531328 is an abundant number, since it is smaller than the sum of its proper divisors (35348903880).

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

21242531328 is an equidigital number, since it uses as much as digits as its factorization.

21242531328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13829794 (or 13829778 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The spelling of 21242531328 in words is "twenty-one billion, two hundred forty-two million, five hundred thirty-one thousand, three hundred twenty-eight".