31931817289 has 2 divisors, whose sum is σ = 31931817290. Its totient is φ = 31931817288.

The previous prime is 31931817283. The next prime is 31931817299. The reversal of 31931817289 is 98271813913.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31625287225 + 306530064 = 177835^2 + 17508^2 .

It is a cyclic number.

It is not a de Polignac number, because 31931817289 - 2⁷ = 31931817161 is a prime.

It is not a weakly prime, because it can be changed into another prime (31931817283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15965908644 + 15965908645.

It is an arithmetic number, because the mean of its divisors is an integer number (15965908645).

Almost surely, 2^31931817289 is an apocalyptic number.

It is an amenable number.

31931817289 is a deficient number, since it is larger than the sum of its proper divisors (1).

31931817289 is an equidigital number, since it uses as much as digits as its factorization.

31931817289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 52.

The spelling of 31931817289 in words is "thirty-one billion, nine hundred thirty-one million, eight hundred seventeen thousand, two hundred eighty-nine".