636117997 has 4 divisors (see below), whose sum is σ = 636245596. Its totient is φ = 635990400.

The previous prime is 636117983. The next prime is 636118003. The reversal of 636117997 is 799711636.

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

It can be written as a sum of positive squares in 2 ways, for example, as 143544361 + 492573636 = 11981^2 + 22194^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-636117997 is a prime.

It is a super-2 number, since 2×636117997² = 809292212214584018, which contains 22 as substring.

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 636117997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636111997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56004 + ... + 66397.

It is an arithmetic number, because the mean of its divisors is an integer number (159061399).

Almost surely, 2^636117997 is an apocalyptic number.

It is an amenable number.

636117997 is a deficient number, since it is larger than the sum of its proper divisors (127599).

636117997 is a wasteful number, since it uses less digits than its factorization.

636117997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127598.

The product of its digits is 428652, while the sum is 49.

The square root of 636117997 is about 25221.3797600369. The cubic root of 636117997 is about 860.0279407724.

The spelling of 636117997 in words is "six hundred thirty-six million, one hundred seventeen thousand, nine hundred ninety-seven".