21012033231 has 32 divisors (see below), whose sum is σ = 35585464320. Its totient is φ = 12003658272.

The previous prime is 21012033209. The next prime is 21012033247. The reversal of 21012033231 is 13233021012.

21012033231 is a `hidden beast` number, since 210 + 120 + 332 + 3 + 1 = 666.

It is not a de Polignac number, because 21012033231 - 2⁹ = 21012032719 is a prime.

It is a super-2 number, since 2×21012033231² (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 (21012033281) 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, 813786 + ... + 839208.

It is an arithmetic number, because the mean of its divisors is an integer number (1112045760).

Almost surely, 2^21012033231 is an apocalyptic number.

21012033231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21012033231 is a deficient number, since it is larger than the sum of its proper divisors (14573431089).

21012033231 is a wasteful number, since it uses less digits than its factorization.

21012033231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29812 (or 29806 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21012033231 its reverse (13233021012), we get a palindrome (34245054243).

The spelling of 21012033231 in words is "twenty-one billion, twelve million, thirty-three thousand, two hundred thirty-one".