31310200021 has 4 divisors (see below), whose sum is σ = 31315597632. Its totient is φ = 31304802412.

The previous prime is 31310200013. The next prime is 31310200037. The reversal of 31310200021 is 12000201313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31310200021 - 2³ = 31310200013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31310199974 and 31310200010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31310200921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2690095 + ... + 2701708.

It is an arithmetic number, because the mean of its divisors is an integer number (7828899408).

Almost surely, 2^31310200021 is an apocalyptic number.

It is an amenable number.

31310200021 is a deficient number, since it is larger than the sum of its proper divisors (5397611).

31310200021 is an equidigital number, since it uses as much as digits as its factorization.

31310200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5397610.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 31310200021 its reverse (12000201313), we get a palindrome (43310401334).

The spelling of 31310200021 in words is "thirty-one billion, three hundred ten million, two hundred thousand, twenty-one".