636392161 has 6 divisors (see below), whose sum is σ = 676029350. Its totient is φ = 598957056.

The previous prime is 636392123. The next prime is 636392167. The reversal of 636392161 is 161293636.

It can be written as a sum of positive squares in 3 ways, for example, as 253446400 + 382945761 = 15920^2 + 19569^2 .

It is not a de Polignac number, because 636392161 - 2²¹ = 634295009 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 636392161.

It is not an unprimeable number, because it can be changed into a prime (636392167) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1100736 + ... + 1101313.

Almost surely, 2^636392161 is an apocalyptic number.

It is an amenable number.

636392161 is a deficient number, since it is larger than the sum of its proper divisors (39637189).

636392161 is a wasteful number, since it uses less digits than its factorization.

636392161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2202083 (or 2202066 counting only the distinct ones).

The product of its digits is 34992, while the sum is 37.

The square root of 636392161 is about 25226.8143252373. The cubic root of 636392161 is about 860.1514790860.

The spelling of 636392161 in words is "six hundred thirty-six million, three hundred ninety-two thousand, one hundred sixty-one".