31668157 has 2 divisors, whose sum is σ = 31668158. Its totient is φ = 31668156.

The previous prime is 31668151. The next prime is 31668163. The reversal of 31668157 is 75186613.

It is a balanced prime because it is at equal distance from previous prime (31668151) and next prime (31668163).

It can be written as a sum of positive squares in only one way, i.e., 16760836 + 14907321 = 4094^2 + 3861^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31668157 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 (31668151) 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, 15834078 + 15834079.

It is an arithmetic number, because the mean of its divisors is an integer number (15834079).

Almost surely, 2^31668157 is an apocalyptic number.

It is an amenable number.

31668157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31668157 is an equidigital number, since it uses as much as digits as its factorization.

31668157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 37.

The square root of 31668157 is about 5627.4467567450. The cubic root of 31668157 is about 316.3789617096.

The spelling of 31668157 in words is "thirty-one million, six hundred sixty-eight thousand, one hundred fifty-seven".