31311197 has 2 divisors, whose sum is σ = 31311198. Its totient is φ = 31311196.

The previous prime is 31311191. The next prime is 31311223. The reversal of 31311197 is 79111313.

It is an a-pointer prime, because the next prime (31311223) can be obtained adding 31311197 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27394756 + 3916441 = 5234^2 + 1979^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31311197 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31311191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15655598 + 15655599.

It is an arithmetic number, because the mean of its divisors is an integer number (15655599).

Almost surely, 2^31311197 is an apocalyptic number.

It is an amenable number.

31311197 is a deficient number, since it is larger than the sum of its proper divisors (1).

31311197 is an equidigital number, since it uses as much as digits as its factorization.

31311197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 567, while the sum is 26.

The square root of 31311197 is about 5595.6408926950. The cubic root of 31311197 is about 315.1857374405.

The spelling of 31311197 in words is "thirty-one million, three hundred eleven thousand, one hundred ninety-seven".