31517149 has 2 divisors, whose sum is σ = 31517150. Its totient is φ = 31517148.

The previous prime is 31517063. The next prime is 31517197. The reversal of 31517149 is 94171513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31416025 + 101124 = 5605^2 + 318^2 .

It is a cyclic number.

It is not a de Polignac number, because 31517149 - 2⁷ = 31517021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31517149.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31517749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15758574 + 15758575.

It is an arithmetic number, because the mean of its divisors is an integer number (15758575).

Almost surely, 2^31517149 is an apocalyptic number.

It is an amenable number.

31517149 is a deficient number, since it is larger than the sum of its proper divisors (1).

31517149 is an equidigital number, since it uses as much as digits as its factorization.

31517149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 31.

The square root of 31517149 is about 5614.0136266311. The cubic root of 31517149 is about 315.8752812584.

The spelling of 31517149 in words is "thirty-one million, five hundred seventeen thousand, one hundred forty-nine".