636942816739 has 2 divisors, whose sum is σ = 636942816740. Its totient is φ = 636942816738.

The previous prime is 636942816709. The next prime is 636942816767. The reversal of 636942816739 is 937618249636.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 636942816739 - 2¹¹ = 636942814691 is a prime.

It is a super-2 number, since 2×636942816739² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (636942816709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318471408369 + 318471408370.

It is an arithmetic number, because the mean of its divisors is an integer number (318471408370).

Almost surely, 2^636942816739 is an apocalyptic number.

636942816739 is a deficient number, since it is larger than the sum of its proper divisors (1).

636942816739 is an equidigital number, since it uses as much as digits as its factorization.

636942816739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70543872, while the sum is 64.

The spelling of 636942816739 in words is "six hundred thirty-six billion, nine hundred forty-two million, eight hundred sixteen thousand, seven hundred thirty-nine".