639379735 has 24 divisors (see below), whose sum is σ = 823179456. Its totient is φ = 476556480.

The previous prime is 639379729. The next prime is 639379739. The reversal of 639379735 is 537973936.

It is a de Polignac number, because none of the positive numbers 2^k-639379735 is a prime.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639379739) 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 23 ways as a sum of consecutive naturals, for example, 107202 + ... + 113008.

It is an arithmetic number, because the mean of its divisors is an integer number (34299144).

Almost surely, 2^639379735 is an apocalyptic number.

639379735 is a deficient number, since it is larger than the sum of its proper divisors (183799721).

639379735 is a wasteful number, since it uses less digits than its factorization.

639379735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5911 (or 5892 counting only the distinct ones).

The product of its digits is 3214890, while the sum is 52.

The square root of 639379735 is about 25285.9592461904. The cubic root of 639379735 is about 861.4953859356.

The spelling of 639379735 in words is "six hundred thirty-nine million, three hundred seventy-nine thousand, seven hundred thirty-five".