21052551231 has 12 divisors (see below), whose sum is σ = 30602932152. Its totient is φ = 13945638096.

The previous prime is 21052551181. The next prime is 21052551253. The reversal of 21052551231 is 13215525012.

21052551231 is a `hidden beast` number, since 2 + 10 + 525 + 5 + 123 + 1 = 666.

It is not a de Polignac number, because 21052551231 - 2⁶ = 21052551167 is a prime.

It is a super-2 number, since 2×21052551231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21052551195 and 21052551204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052558231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7448181 + ... + 7451006.

It is an arithmetic number, because the mean of its divisors is an integer number (2550244346).

Almost surely, 2^21052551231 is an apocalyptic number.

21052551231 is a deficient number, since it is larger than the sum of its proper divisors (9550380921).

21052551231 is a wasteful number, since it uses less digits than its factorization.

21052551231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14899350 (or 14899347 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The spelling of 21052551231 in words is "twenty-one billion, fifty-two million, five hundred fifty-one thousand, two hundred thirty-one".