639279305 has 32 divisors (see below), whose sum is σ = 930092544. Its totient is φ = 411780096.

The previous prime is 639279293. The next prime is 639279343. The reversal of 639279305 is 503972936.

It is a de Polignac number, because none of the positive numbers 2^k-639279305 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 584339 + ... + 585431.

It is an arithmetic number, because the mean of its divisors is an integer number (29065392).

Almost surely, 2^639279305 is an apocalyptic number.

It is an amenable number.

639279305 is a deficient number, since it is larger than the sum of its proper divisors (290813239).

639279305 is a wasteful number, since it uses less digits than its factorization.

639279305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2105.

The product of its (nonzero) digits is 306180, while the sum is 44.

The square root of 639279305 is about 25283.9732834853. The cubic root of 639279305 is about 861.4502773680.

The spelling of 639279305 in words is "six hundred thirty-nine million, two hundred seventy-nine thousand, three hundred five".