3121797817 has 2 divisors, whose sum is σ = 3121797818. Its totient is φ = 3121797816.

The previous prime is 3121797697. The next prime is 3121797821. The reversal of 3121797817 is 7187971213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2755305081 + 366492736 = 52491^2 + 19144^2 .

It is a cyclic number.

It is not a de Polignac number, because 3121797817 - 2⁷ = 3121797689 is a prime.

It is a super-2 number, since 2×3121797817² = 19491243220451930978, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (3121797517) 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, 1560898908 + 1560898909.

It is an arithmetic number, because the mean of its divisors is an integer number (1560898909).

Almost surely, 2^3121797817 is an apocalyptic number.

It is an amenable number.

3121797817 is a deficient number, since it is larger than the sum of its proper divisors (1).

3121797817 is an equidigital number, since it uses as much as digits as its factorization.

3121797817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 148176, while the sum is 46.

The square root of 3121797817 is about 55873.0509011276. The cubic root of 3121797817 is about 1461.5093256461.

The spelling of 3121797817 in words is "three billion, one hundred twenty-one million, seven hundred ninety-seven thousand, eight hundred seventeen".