31189957 has 2 divisors, whose sum is σ = 31189958. Its totient is φ = 31189956.

The previous prime is 31189913. The next prime is 31189969. The reversal of 31189957 is 75998113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23824161 + 7365796 = 4881^2 + 2714^2 .

It is an emirp because it is prime and its reverse (75998113) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31189957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31189057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15594978 + 15594979.

It is an arithmetic number, because the mean of its divisors is an integer number (15594979).

Almost surely, 2^31189957 is an apocalyptic number.

It is an amenable number.

31189957 is a deficient number, since it is larger than the sum of its proper divisors (1).

31189957 is an equidigital number, since it uses as much as digits as its factorization.

31189957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 43.

The square root of 31189957 is about 5584.7969524415. The cubic root of 31189957 is about 314.7784012958.

The spelling of 31189957 in words is "thirty-one million, one hundred eighty-nine thousand, nine hundred fifty-seven".