31320213157 has 2 divisors, whose sum is σ = 31320213158. Its totient is φ = 31320213156.

The previous prime is 31320213097. The next prime is 31320213203. The reversal of 31320213157 is 75131202313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30378398436 + 941814721 = 174294^2 + 30689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31320213157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31320210157) 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, 15660106578 + 15660106579.

It is an arithmetic number, because the mean of its divisors is an integer number (15660106579).

Almost surely, 2^31320213157 is an apocalyptic number.

It is an amenable number.

31320213157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31320213157 is an equidigital number, since it uses as much as digits as its factorization.

31320213157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 28.

The spelling of 31320213157 in words is "thirty-one billion, three hundred twenty million, two hundred thirteen thousand, one hundred fifty-seven".