21211023231 has 16 divisors (see below), whose sum is σ = 31734868320. Its totient is φ = 14000673600.

The previous prime is 21211023193. The next prime is 21211023259. The reversal of 21211023231 is 13232011212.

It is not a de Polignac number, because 21211023231 - 2¹⁹ = 21210498943 is a prime.

It is a super-2 number, since 2×21211023231² (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 (21211024231) 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 15 ways as a sum of consecutive naturals, for example, 3886350 + ... + 3891803.

It is an arithmetic number, because the mean of its divisors is an integer number (1983429270).

Almost surely, 2^21211023231 is an apocalyptic number.

21211023231 is a deficient number, since it is larger than the sum of its proper divisors (10523845089).

21211023231 is a wasteful number, since it uses less digits than its factorization.

21211023231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7778263 (or 7778257 counting only the distinct ones).

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

Adding to 21211023231 its reverse (13232011212), we get a palindrome (34443034443).

The spelling of 21211023231 in words is "twenty-one billion, two hundred eleven million, twenty-three thousand, two hundred thirty-one".