636768646 has 4 divisors (see below), whose sum is σ = 955152972. Its totient is φ = 318384322.

The previous prime is 636768637. The next prime is 636768647. The reversal of 636768646 is 646867636.

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

It is a junction number, because it is equal to n+sod(n) for n = 636768593 and 636768602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636768647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159192160 + ... + 159192163.

It is an arithmetic number, because the mean of its divisors is an integer number (238788243).

Almost surely, 2^636768646 is an apocalyptic number.

636768646 is a deficient number, since it is larger than the sum of its proper divisors (318384326).

636768646 is a wasteful number, since it uses less digits than its factorization.

636768646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318384325.

The product of its digits is 5225472, while the sum is 52.

The square root of 636768646 is about 25234.2752224034. The cubic root of 636768646 is about 860.3210654465.

The spelling of 636768646 in words is "six hundred thirty-six million, seven hundred sixty-eight thousand, six hundred forty-six".