636990689 has 4 divisors (see below), whose sum is σ = 637101360. Its totient is φ = 636880020.

The previous prime is 636990677. The next prime is 636990701. The reversal of 636990689 is 986099636.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (636990677) and next prime (636990701).

It is a cyclic number.

It is not a de Polignac number, because 636990689 - 2¹² = 636986593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (636900689) 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, 46199 + ... + 58380.

It is an arithmetic number, because the mean of its divisors is an integer number (159275340).

Almost surely, 2^636990689 is an apocalyptic number.

It is an amenable number.

636990689 is a deficient number, since it is larger than the sum of its proper divisors (110671).

636990689 is a wasteful number, since it uses less digits than its factorization.

636990689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110670.

The product of its (nonzero) digits is 3779136, while the sum is 56.

The square root of 636990689 is about 25238.6744699479. The cubic root of 636990689 is about 860.4210526092.

The spelling of 636990689 in words is "six hundred thirty-six million, nine hundred ninety thousand, six hundred eighty-nine".