639799163 has 4 divisors (see below), whose sum is σ = 643373640. Its totient is φ = 636224688.

The previous prime is 639799151. The next prime is 639799169. The reversal of 639799163 is 361997936.

It is a happy number.

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 639799163 - 2¹⁴ = 639782779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639799169) 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, 1786970 + ... + 1787327.

It is an arithmetic number, because the mean of its divisors is an integer number (160843410).

Almost surely, 2^639799163 is an apocalyptic number.

639799163 is a deficient number, since it is larger than the sum of its proper divisors (3574477).

639799163 is a wasteful number, since it uses less digits than its factorization.

639799163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3574476.

The product of its digits is 1653372, while the sum is 53.

The square root of 639799163 is about 25294.2515801516. The cubic root of 639799163 is about 861.6837227902.

The spelling of 639799163 in words is "six hundred thirty-nine million, seven hundred ninety-nine thousand, one hundred sixty-three".