639769767 has 32 divisors (see below), whose sum is σ = 1105144320. Its totient is φ = 319697280.

The previous prime is 639769759. The next prime is 639769777. The reversal of 639769767 is 767967936.

It is not a de Polignac number, because 639769767 - 2³ = 639769759 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 639769767.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639769747) 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 31 ways as a sum of consecutive naturals, for example, 56484 + ... + 66857.

It is an arithmetic number, because the mean of its divisors is an integer number (34535760).

Almost surely, 2^639769767 is an apocalyptic number.

639769767 is a deficient number, since it is larger than the sum of its proper divisors (465374553).

639769767 is a wasteful number, since it uses less digits than its factorization.

639769767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123383.

The product of its digits is 18003384, while the sum is 60.

The square root of 639769767 is about 25293.6704928328. The cubic root of 639769767 is about 861.6705257100.

The spelling of 639769767 in words is "six hundred thirty-nine million, seven hundred sixty-nine thousand, seven hundred sixty-seven".