31213121233 has 4 divisors (see below), whose sum is σ = 35672138560. Its totient is φ = 26754103908.

The previous prime is 31213121213. The next prime is 31213121237. The reversal of 31213121233 is 33212131213.

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 not a de Polignac number, because 31213121233 - 2¹⁷ = 31212990161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31213121237) 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, 2229508653 + ... + 2229508666.

It is an arithmetic number, because the mean of its divisors is an integer number (8918034640).

Almost surely, 2^31213121233 is an apocalyptic number.

It is an amenable number.

31213121233 is a deficient number, since it is larger than the sum of its proper divisors (4459017327).

31213121233 is an equidigital number, since it uses as much as digits as its factorization.

31213121233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4459017326.

The product of its digits is 648, while the sum is 22.

Adding to 31213121233 its reverse (33212131213), we get a palindrome (64425252446).

The spelling of 31213121233 in words is "thirty-one billion, two hundred thirteen million, one hundred twenty-one thousand, two hundred thirty-three".