21407511231 has 12 divisors (see below), whose sum is σ = 31383483352. Its totient is φ = 14058663696.

The previous prime is 21407511221. The next prime is 21407511269. The reversal of 21407511231 is 13211570412.

21407511231 is a `hidden beast` number, since 2 + 140 + 7 + 511 + 2 + 3 + 1 = 666.

It is not a de Polignac number, because 21407511231 - 2¹¹ = 21407509183 is a prime.

It is a super-2 number, since 2×21407511231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21407511195 and 21407511204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21407511221) 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, 17750236 + ... + 17751441.

Almost surely, 2^21407511231 is an apocalyptic number.

21407511231 is a deficient number, since it is larger than the sum of its proper divisors (9975972121).

21407511231 is a wasteful number, since it uses less digits than its factorization.

21407511231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35501750 (or 35501747 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The spelling of 21407511231 in words is "twenty-one billion, four hundred seven million, five hundred eleven thousand, two hundred thirty-one".