21031203231 has 16 divisors (see below), whose sum is σ = 31235836000. Its totient is φ = 13985478144.

The previous prime is 21031203211. The next prime is 21031203247. The reversal of 21031203231 is 13230213012.

It is not a de Polignac number, because 21031203231 - 2⁵ = 21031203199 is a prime.

It is a super-2 number, since 2×21031203231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031203211) 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, 970306 + ... + 991743.

It is an arithmetic number, because the mean of its divisors is an integer number (1952239750).

Almost surely, 2^21031203231 is an apocalyptic number.

21031203231 is a deficient number, since it is larger than the sum of its proper divisors (10204632769).

21031203231 is a wasteful number, since it uses less digits than its factorization.

21031203231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1962455 (or 1962449 counting only the distinct ones).

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

Adding to 21031203231 its reverse (13230213012), we get a palindrome (34261416243).

The spelling of 21031203231 in words is "twenty-one billion, thirty-one million, two hundred three thousand, two hundred thirty-one".