31319513 has 2 divisors, whose sum is σ = 31319514. Its totient is φ = 31319512.

The previous prime is 31319489. The next prime is 31319521. The reversal of 31319513 is 31591313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28590409 + 2729104 = 5347^2 + 1652^2 .

It is a cyclic number.

It is not a de Polignac number, because 31319513 - 2¹⁶ = 31253977 is a prime.

It is not a weakly prime, because it can be changed into another prime (31319573) 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, 15659756 + 15659757.

It is an arithmetic number, because the mean of its divisors is an integer number (15659757).

Almost surely, 2^31319513 is an apocalyptic number.

It is an amenable number.

31319513 is a deficient number, since it is larger than the sum of its proper divisors (1).

31319513 is an equidigital number, since it uses as much as digits as its factorization.

31319513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1215, while the sum is 26.

The square root of 31319513 is about 5596.3839217838. The cubic root of 31319513 is about 315.2136385625.

The spelling of 31319513 in words is "thirty-one million, three hundred nineteen thousand, five hundred thirteen".