31213303421 has 2 divisors, whose sum is σ = 31213303422. Its totient is φ = 31213303420.

The previous prime is 31213303399. The next prime is 31213303447. The reversal of 31213303421 is 12430331213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15939062500 + 15274240921 = 126250^2 + 123589^2 .

It is a cyclic number.

It is not a de Polignac number, because 31213303421 - 2⁶ = 31213303357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31213303021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606651710 + 15606651711.

It is an arithmetic number, because the mean of its divisors is an integer number (15606651711).

Almost surely, 2^31213303421 is an apocalyptic number.

It is an amenable number.

31213303421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31213303421 is an equidigital number, since it uses as much as digits as its factorization.

31213303421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 31213303421 its reverse (12430331213), we get a palindrome (43643634634).

The spelling of 31213303421 in words is "thirty-one billion, two hundred thirteen million, three hundred three thousand, four hundred twenty-one".