31605213217157 has 2 divisors, whose sum is σ = 31605213217158. Its totient is φ = 31605213217156.

The previous prime is 31605213217133. The next prime is 31605213217169. The reversal of 31605213217157 is 75171231250613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26984222393956 + 4620990823201 = 5194634^2 + 2149649^2 .

It is a cyclic number.

It is not a de Polignac number, because 31605213217157 - 2⁸ = 31605213216901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31605213217187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15802606608578 + 15802606608579.

It is an arithmetic number, because the mean of its divisors is an integer number (15802606608579).

Almost surely, 2^{31605213217157} is an apocalyptic number.

It is an amenable number.

31605213217157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31605213217157 is an equidigital number, since it uses as much as digits as its factorization.

31605213217157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 264600, while the sum is 44.

The spelling of 31605213217157 in words is "thirty-one trillion, six hundred five billion, two hundred thirteen million, two hundred seventeen thousand, one hundred fifty-seven".