639779883 has 4 divisors (see below), whose sum is σ = 853039848. Its totient is φ = 426519920.

The previous prime is 639779879. The next prime is 639779909. The reversal of 639779883 is 388977936.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 639779883 - 2² = 639779879 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639779863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106629978 + ... + 106629983.

It is an arithmetic number, because the mean of its divisors is an integer number (213259962).

Almost surely, 2^639779883 is an apocalyptic number.

639779883 is a deficient number, since it is larger than the sum of its proper divisors (213259965).

639779883 is a wasteful number, since it uses less digits than its factorization.

639779883 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213259964.

The product of its digits is 13716864, while the sum is 60.

The square root of 639779883 is about 25293.8704630193. The cubic root of 639779883 is about 861.6750672464.

The spelling of 639779883 in words is "six hundred thirty-nine million, seven hundred seventy-nine thousand, eight hundred eighty-three".