639335669 has 16 divisors (see below), whose sum is σ = 765096192. Its totient is φ = 522348288.

The previous prime is 639335657. The next prime is 639335681. The reversal of 639335669 is 966533936.

It is an interprime number because it is at equal distance from previous prime (639335657) and next prime (639335681).

It is not a de Polignac number, because 639335669 - 2²⁰ = 638287093 is a prime.

It is a super-2 number, since 2×639335669² = 817500195311355122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639335629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40397 + ... + 53949.

It is an arithmetic number, because the mean of its divisors is an integer number (47818512).

Almost surely, 2^639335669 is an apocalyptic number.

It is an amenable number.

639335669 is a deficient number, since it is larger than the sum of its proper divisors (125760523).

639335669 is a wasteful number, since it uses less digits than its factorization.

639335669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13876.

The product of its digits is 2361960, while the sum is 50.

The square root of 639335669 is about 25285.0878780359. The cubic root of 639335669 is about 861.4755940833.

The spelling of 639335669 in words is "six hundred thirty-nine million, three hundred thirty-five thousand, six hundred sixty-nine".