31358161 has 2 divisors, whose sum is σ = 31358162. Its totient is φ = 31358160.

The previous prime is 31358123. The next prime is 31358167. The reversal of 31358161 is 16185313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17808400 + 13549761 = 4220^2 + 3681^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31358161 is a prime.

It is a super-2 number, since 2×31358161² = 1966668522603842, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31358167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15679080 + 15679081.

It is an arithmetic number, because the mean of its divisors is an integer number (15679081).

Almost surely, 2^31358161 is an apocalyptic number.

It is an amenable number.

31358161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31358161 is an equidigital number, since it uses as much as digits as its factorization.

31358161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 28.

The square root of 31358161 is about 5599.8358011642. The cubic root of 31358161 is about 315.3432422077.

The spelling of 31358161 in words is "thirty-one million, three hundred fifty-eight thousand, one hundred sixty-one".