31085993 has 2 divisors, whose sum is σ = 31085994. Its totient is φ = 31085992.

The previous prime is 31085987. The next prime is 31086023. The reversal of 31085993 is 39958013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31047184 + 38809 = 5572^2 + 197^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31085993 is a prime.

It is not a weakly prime, because it can be changed into another prime (31085933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15542996 + 15542997.

It is an arithmetic number, because the mean of its divisors is an integer number (15542997).

Almost surely, 2^31085993 is an apocalyptic number.

It is an amenable number.

31085993 is a deficient number, since it is larger than the sum of its proper divisors (1).

31085993 is an equidigital number, since it uses as much as digits as its factorization.

31085993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 31085993 is about 5575.4814141920. The cubic root of 31085993 is about 314.4282666877.

The spelling of 31085993 in words is "thirty-one million, eighty-five thousand, nine hundred ninety-three".