21242609631 has 12 divisors (see below), whose sum is σ = 30685047120. Its totient is φ = 14161150080.

The previous prime is 21242609627. The next prime is 21242609657. The reversal of 21242609631 is 13690624212.

It is a happy number.

21242609631 is a `hidden beast` number, since 2 + 1 + 2 + 42 + 609 + 6 + 3 + 1 = 666.

It is not a de Polignac number, because 21242609631 - 2² = 21242609627 is a prime.

It is a super-2 number, since 2×21242609631² (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 (21242609431) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 347590 + ... + 404108.

It is an arithmetic number, because the mean of its divisors is an integer number (2557087260).

Almost surely, 2^21242609631 is an apocalyptic number.

21242609631 is a deficient number, since it is larger than the sum of its proper divisors (9442437489).

21242609631 is a wasteful number, since it uses less digits than its factorization.

21242609631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98286 (or 98283 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

It can be divided in two parts, 2124 and 2609631, that added together give a triangular number (2611755 = T₂₂₈₅).

The spelling of 21242609631 in words is "twenty-one billion, two hundred forty-two million, six hundred nine thousand, six hundred thirty-one".