31685393 has 2 divisors, whose sum is σ = 31685394. Its totient is φ = 31685392.

The previous prime is 31685347. The next prime is 31685443. The reversal of 31685393 is 39358613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26450449 + 5234944 = 5143^2 + 2288^2 .

It is a cyclic number.

It is not a de Polignac number, because 31685393 - 2²⁴ = 14908177 is a prime.

It is not a weakly prime, because it can be changed into another prime (31685323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15842696 + 15842697.

It is an arithmetic number, because the mean of its divisors is an integer number (15842697).

Almost surely, 2^31685393 is an apocalyptic number.

It is an amenable number.

31685393 is a deficient number, since it is larger than the sum of its proper divisors (1).

31685393 is an equidigital number, since it uses as much as digits as its factorization.

31685393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58320, while the sum is 38.

The square root of 31685393 is about 5628.9779711774. The cubic root of 31685393 is about 316.4363497326.

The spelling of 31685393 in words is "thirty-one million, six hundred eighty-five thousand, three hundred ninety-three".