21122013231 has 24 divisors (see below), whose sum is σ = 33739117776. Its totient is φ = 12625856640.

The previous prime is 21122013217. The next prime is 21122013257. The reversal of 21122013231 is 13231022112.

21122013231 is a `hidden beast` number, since 211 + 220 + 1 + 3 + 231 = 666.

It is not a de Polignac number, because 21122013231 - 2¹⁸ = 21121751087 is a prime.

It is a super-2 number, since 2×21122013231² (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 (21122013431) 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 23 ways as a sum of consecutive naturals, for example, 1454100 + ... + 1468553.

It is an arithmetic number, because the mean of its divisors is an integer number (1405796574).

Almost surely, 2^21122013231 is an apocalyptic number.

21122013231 is a deficient number, since it is larger than the sum of its proper divisors (12617104545).

21122013231 is a wasteful number, since it uses less digits than its factorization.

21122013231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2922743 (or 2922740 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21122013231 its reverse (13231022112), we get a palindrome (34353035343).

The spelling of 21122013231 in words is "twenty-one billion, one hundred twenty-two million, thirteen thousand, two hundred thirty-one".