639744293 has 8 divisors (see below), whose sum is σ = 649187136. Its totient is φ = 630313600.

The previous prime is 639744283. The next prime is 639744299. The reversal of 639744293 is 392447936.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 639744293 - 2⁴ = 639744277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639744299) 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, 208853 + ... + 211893.

It is an arithmetic number, because the mean of its divisors is an integer number (81148392).

Almost surely, 2^639744293 is an apocalyptic number.

It is an amenable number.

639744293 is a deficient number, since it is larger than the sum of its proper divisors (9442843).

639744293 is a wasteful number, since it uses less digits than its factorization.

639744293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6075.

The product of its digits is 979776, while the sum is 47.

The square root of 639744293 is about 25293.1669231040. The cubic root of 639744293 is about 861.6590890508.

The spelling of 639744293 in words is "six hundred thirty-nine million, seven hundred forty-four thousand, two hundred ninety-three".