31331117 has 2 divisors, whose sum is σ = 31331118. Its totient is φ = 31331116.

The previous prime is 31331101. The next prime is 31331137. The reversal of 31331117 is 71113313.

It is an a-pointer prime, because the next prime (31331137) can be obtained adding 31331117 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25210441 + 6120676 = 5021^2 + 2474^2 .

It is a cyclic number.

It is not a de Polignac number, because 31331117 - 2⁴ = 31331101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31331137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15665558 + 15665559.

It is an arithmetic number, because the mean of its divisors is an integer number (15665559).

Almost surely, 2^31331117 is an apocalyptic number.

It is an amenable number.

31331117 is a deficient number, since it is larger than the sum of its proper divisors (1).

31331117 is an equidigital number, since it uses as much as digits as its factorization.

31331117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 189, while the sum is 20.

The square root of 31331117 is about 5597.4205666539. The cubic root of 31331117 is about 315.2525630441.

The spelling of 31331117 in words is "thirty-one million, three hundred thirty-one thousand, one hundred seventeen".