31820478757 has 2 divisors, whose sum is σ = 31820478758. Its totient is φ = 31820478756.

The previous prime is 31820478721. The next prime is 31820478769. The reversal of 31820478757 is 75787402813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25610881156 + 6209597601 = 160034^2 + 78801^2 .

It is an emirp because it is prime and its reverse (75787402813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31820478757 - 2⁷ = 31820478629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31820478707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15910239378 + 15910239379.

It is an arithmetic number, because the mean of its divisors is an integer number (15910239379).

Almost surely, 2^31820478757 is an apocalyptic number.

It is an amenable number.

31820478757 is a deficient number, since it is larger than the sum of its proper divisors (1).

31820478757 is an equidigital number, since it uses as much as digits as its factorization.

31820478757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2634240, while the sum is 52.

The spelling of 31820478757 in words is "thirty-one billion, eight hundred twenty million, four hundred seventy-eight thousand, seven hundred fifty-seven".