21464991531 has 6 divisors (see below), whose sum is σ = 31004987780. Its totient is φ = 14309994348.

The previous prime is 21464991439. The next prime is 21464991533. The reversal of 21464991531 is 13519946412.

21464991531 is a `hidden beast` number, since 2 + 1 + 4 + 6 + 499 + 153 + 1 = 666.

It is not a de Polignac number, because 21464991531 - 2⁹ = 21464991019 is a prime.

It is a super-2 number, since 2×21464991531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21464991533) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1192499521 + ... + 1192499538.

Almost surely, 2^21464991531 is an apocalyptic number.

21464991531 is a deficient number, since it is larger than the sum of its proper divisors (9539996249).

21464991531 is a wasteful number, since it uses less digits than its factorization.

21464991531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2384999065 (or 2384999062 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The spelling of 21464991531 in words is "twenty-one billion, four hundred sixty-four million, nine hundred ninety-one thousand, five hundred thirty-one".