636161887 has 4 divisors (see below), whose sum is σ = 642338320. Its totient is φ = 629985456.

The previous prime is 636161861. The next prime is 636161891. The reversal of 636161887 is 788161636.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 636161887 - 2¹⁵ = 636129119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636161087) 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 in 3 ways as a sum of consecutive naturals, for example, 3088062 + ... + 3088267.

It is an arithmetic number, because the mean of its divisors is an integer number (160584580).

Almost surely, 2^636161887 is an apocalyptic number.

636161887 is a deficient number, since it is larger than the sum of its proper divisors (6176433).

636161887 is a wasteful number, since it uses less digits than its factorization.

636161887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6176432.

The product of its digits is 290304, while the sum is 46.

The square root of 636161887 is about 25222.2498401709. The cubic root of 636161887 is about 860.0477199949.

The spelling of 636161887 in words is "six hundred thirty-six million, one hundred sixty-one thousand, eight hundred eighty-seven".