21246561231 has 16 divisors (see below), whose sum is σ = 32496076800. Its totient is φ = 12095755488.

The previous prime is 21246561229. The next prime is 21246561239. The reversal of 21246561231 is 13216564212.

It is not a de Polignac number, because 21246561231 - 2¹ = 21246561229 is a prime.

It is a super-2 number, since 2×21246561231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21246561192 and 21246561201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21246561239) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1874911 + ... + 1886208.

It is an arithmetic number, because the mean of its divisors is an integer number (2031004800).

Almost surely, 2^21246561231 is an apocalyptic number.

21246561231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21246561231 is a deficient number, since it is larger than the sum of its proper divisors (11249515569).

21246561231 is a wasteful number, since it uses less digits than its factorization.

21246561231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3761398.

The product of its digits is 17280, while the sum is 33.

The spelling of 21246561231 in words is "twenty-one billion, two hundred forty-six million, five hundred sixty-one thousand, two hundred thirty-one".