31320203231 has 4 divisors (see below), whose sum is σ = 32968635000. Its totient is φ = 29671771464.

The previous prime is 31320203227. The next prime is 31320203263. The reversal of 31320203231 is 13230202313.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31320203231 - 2² = 31320203227 is a prime.

It is a super-2 number, since 2×31320203231² (a number of 22 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 (31320203531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 824215856 + ... + 824215893.

It is an arithmetic number, because the mean of its divisors is an integer number (8242158750).

Almost surely, 2^31320203231 is an apocalyptic number.

31320203231 is a deficient number, since it is larger than the sum of its proper divisors (1648431769).

31320203231 is a wasteful number, since it uses less digits than its factorization.

31320203231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1648431768.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 31320203231 its reverse (13230202313), we get a palindrome (44550405544).

The spelling of 31320203231 in words is "thirty-one billion, three hundred twenty million, two hundred three thousand, two hundred thirty-one".