31371157 has 2 divisors, whose sum is σ = 31371158. Its totient is φ = 31371156.

The previous prime is 31371139. The next prime is 31371169. The reversal of 31371157 is 75117313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18740241 + 12630916 = 4329^2 + 3554^2 .

It is an emirp because it is prime and its reverse (75117313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31371157 - 2⁷ = 31371029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31371107) 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, 15685578 + 15685579.

It is an arithmetic number, because the mean of its divisors is an integer number (15685579).

Almost surely, 2^31371157 is an apocalyptic number.

It is an amenable number.

31371157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31371157 is an equidigital number, since it uses as much as digits as its factorization.

31371157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2205, while the sum is 28.

The square root of 31371157 is about 5600.9960721286. The cubic root of 31371157 is about 315.3867995532.

The spelling of 31371157 in words is "thirty-one million, three hundred seventy-one thousand, one hundred fifty-seven".