639008999 has 8 divisors (see below), whose sum is σ = 654210000. Its totient is φ = 623953792.

The previous prime is 639008989. The next prime is 639009001. The reversal of 639008999 is 999800936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 639008999 - 2²⁰ = 637960423 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639008999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639008989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27554 + ... + 45135.

It is an arithmetic number, because the mean of its divisors is an integer number (81776250).

Almost surely, 2^639008999 is an apocalyptic number.

639008999 is a deficient number, since it is larger than the sum of its proper divisors (15201001).

639008999 is a wasteful number, since it uses less digits than its factorization.

639008999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72897.

The product of its (nonzero) digits is 944784, while the sum is 53.

The square root of 639008999 is about 25278.6273163714. The cubic root of 639008999 is about 861.3288447882.

The spelling of 639008999 in words is "six hundred thirty-nine million, eight thousand, nine hundred ninety-nine".