31102157 has 2 divisors, whose sum is σ = 31102158. Its totient is φ = 31102156.

The previous prime is 31102153. The next prime is 31102199. The reversal of 31102157 is 75120113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30980356 + 121801 = 5566^2 + 349^2 .

It is an emirp because it is prime and its reverse (75120113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31102157 - 2² = 31102153 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 (31102153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15551078 + 15551079.

It is an arithmetic number, because the mean of its divisors is an integer number (15551079).

Almost surely, 2^31102157 is an apocalyptic number.

It is an amenable number.

31102157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31102157 is an equidigital number, since it uses as much as digits as its factorization.

31102157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 31102157 is about 5576.9307867321. The cubic root of 31102157 is about 314.4827557287.

The spelling of 31102157 in words is "thirty-one million, one hundred two thousand, one hundred fifty-seven".