636169138 has 16 divisors (see below), whose sum is σ = 1102240224. Its totient is φ = 272157760.

The previous prime is 636169117. The next prime is 636169139. The reversal of 636169138 is 831961636.

It is a super-2 number, since 2×636169138² = 809422344287326088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 636169094 and 636169103.

It is not an unprimeable number, because it can be changed into a prime (636169139) 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 in 7 ways as a sum of consecutive naturals, for example, 850120 + ... + 850867.

It is an arithmetic number, because the mean of its divisors is an integer number (68890014).

Almost surely, 2^636169138 is an apocalyptic number.

636169138 is a deficient number, since it is larger than the sum of its proper divisors (466071086).

636169138 is a wasteful number, since it uses less digits than its factorization.

636169138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1701017.

The product of its digits is 139968, while the sum is 43.

The square root of 636169138 is about 25222.3935818946. The cubic root of 636169138 is about 860.0509876026.

The spelling of 636169138 in words is "six hundred thirty-six million, one hundred sixty-nine thousand, one hundred thirty-eight".