639479179 has 4 divisors (see below), whose sum is σ = 648486000. Its totient is φ = 630472360.

The previous prime is 639479131. The next prime is 639479207. The reversal of 639479179 is 971974936.

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 639479179 - 2⁹ = 639478667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639479119) 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, 4503304 + ... + 4503445.

It is an arithmetic number, because the mean of its divisors is an integer number (162121500).

Almost surely, 2^639479179 is an apocalyptic number.

639479179 is a deficient number, since it is larger than the sum of its proper divisors (9006821).

639479179 is an equidigital number, since it uses as much as digits as its factorization.

639479179 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9006820.

The product of its digits is 2571912, while the sum is 55.

The square root of 639479179 is about 25287.9255574671. The cubic root of 639479179 is about 861.5400469831.

The spelling of 639479179 in words is "six hundred thirty-nine million, four hundred seventy-nine thousand, one hundred seventy-nine".