31997031329 has 2 divisors, whose sum is σ = 31997031330. Its totient is φ = 31997031328.

The previous prime is 31997031307. The next prime is 31997031349. The reversal of 31997031329 is 92313079913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28650640225 + 3346391104 = 169265^2 + 57848^2 .

It is a cyclic number.

It is not a de Polignac number, because 31997031329 - 2¹² = 31997027233 is a prime.

It is not a weakly prime, because it can be changed into another prime (31997031349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15998515664 + 15998515665.

It is an arithmetic number, because the mean of its divisors is an integer number (15998515665).

Almost surely, 2^31997031329 is an apocalyptic number.

It is an amenable number.

31997031329 is a deficient number, since it is larger than the sum of its proper divisors (1).

31997031329 is an equidigital number, since it uses as much as digits as its factorization.

31997031329 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 275562, while the sum is 47.

The spelling of 31997031329 in words is "thirty-one billion, nine hundred ninety-seven million, thirty-one thousand, three hundred twenty-nine".