639754645 has 16 divisors (see below), whose sum is σ = 812655360. Its totient is φ = 482658624.

The previous prime is 639754631. The next prime is 639754649. The reversal of 639754645 is 546457936.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 639754645 - 2²⁷ = 505536917 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639754649) 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 15 ways as a sum of consecutive naturals, for example, 45069 + ... + 57538.

It is an arithmetic number, because the mean of its divisors is an integer number (50790960).

Almost surely, 2^639754645 is an apocalyptic number.

It is an amenable number.

639754645 is a deficient number, since it is larger than the sum of its proper divisors (172900715).

639754645 is a wasteful number, since it uses less digits than its factorization.

639754645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102684.

The product of its digits is 2721600, while the sum is 49.

The square root of 639754645 is about 25293.3715625260. The cubic root of 639754645 is about 861.6637366612.

The spelling of 639754645 in words is "six hundred thirty-nine million, seven hundred fifty-four thousand, six hundred forty-five".