639617229 has 20 divisors (see below), whose sum is σ = 956240736. Its totient is φ = 426071016.

The previous prime is 639617227. The next prime is 639617233. The reversal of 639617229 is 922716936.

It is a happy number.

639617229 is a `hidden beast` number, since 6 + 3 + 9 + 617 + 2 + 29 = 666.

It is not a de Polignac number, because 639617229 - 2¹ = 639617227 is a prime.

It is a super-2 number, since 2×639617229² = 818220399267276882, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639617227) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 137272 + ... + 141854.

Almost surely, 2^639617229 is an apocalyptic number.

It is an amenable number.

639617229 is a deficient number, since it is larger than the sum of its proper divisors (316623507).

639617229 is a wasteful number, since it uses less digits than its factorization.

639617229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6318 (or 6309 counting only the distinct ones).

The product of its digits is 244944, while the sum is 45.

The square root of 639617229 is about 25290.6549737250. The cubic root of 639617229 is about 861.6020386006.

The spelling of 639617229 in words is "six hundred thirty-nine million, six hundred seventeen thousand, two hundred twenty-nine".