31213631209 has 2 divisors, whose sum is σ = 31213631210. Its totient is φ = 31213631208.

The previous prime is 31213631179. The next prime is 31213631213. The reversal of 31213631209 is 90213631213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16538731609 + 14674899600 = 128603^2 + 121140^2 .

It is a cyclic number.

It is not a de Polignac number, because 31213631209 - 2⁷ = 31213631081 is a prime.

It is not a weakly prime, because it can be changed into another prime (31213631249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606815604 + 15606815605.

It is an arithmetic number, because the mean of its divisors is an integer number (15606815605).

Almost surely, 2^31213631209 is an apocalyptic number.

It is an amenable number.

31213631209 is a deficient number, since it is larger than the sum of its proper divisors (1).

31213631209 is an equidigital number, since it uses as much as digits as its factorization.

31213631209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 31.

The spelling of 31213631209 in words is "thirty-one billion, two hundred thirteen million, six hundred thirty-one thousand, two hundred nine".