21312333231 has 32 divisors (see below), whose sum is σ = 34202941440. Its totient is φ = 11531515104.

The previous prime is 21312333199. The next prime is 21312333241. The reversal of 21312333231 is 13233321312.

It is not a de Polignac number, because 21312333231 - 2⁵ = 21312333199 is a prime.

It is a super-2 number, since 2×21312333231² (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 (21312333241) 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 31 ways as a sum of consecutive naturals, for example, 818296 + ... + 843938.

It is an arithmetic number, because the mean of its divisors is an integer number (1068841920).

Almost surely, 2^21312333231 is an apocalyptic number.

21312333231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21312333231 is a deficient number, since it is larger than the sum of its proper divisors (12890608209).

21312333231 is a wasteful number, since it uses less digits than its factorization.

21312333231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27755.

The product of its digits is 1944, while the sum is 24.

Adding to 21312333231 its reverse (13233321312), we get a palindrome (34545654543).

The spelling of 21312333231 in words is "twenty-one billion, three hundred twelve million, three hundred thirty-three thousand, two hundred thirty-one".