639982659 has 32 divisors (see below), whose sum is σ = 909656064. Its totient is φ = 399358080.

The previous prime is 639982639. The next prime is 639982661. The reversal of 639982659 is 956289936.

It is not a de Polignac number, because 639982659 - 2⁵ = 639982627 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 639982599 and 639982608.

It is not an unprimeable number, because it can be changed into a prime (639982639) 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, 1611849 + ... + 1612245.

It is an arithmetic number, because the mean of its divisors is an integer number (28426752).

Almost surely, 2^639982659 is an apocalyptic number.

639982659 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

639982659 is a deficient number, since it is larger than the sum of its proper divisors (269673405).

639982659 is a wasteful number, since it uses less digits than its factorization.

639982659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867.

The product of its digits is 6298560, while the sum is 57.

The square root of 639982659 is about 25297.8785474197. The cubic root of 639982659 is about 861.7660925983.

The spelling of 639982659 in words is "six hundred thirty-nine million, nine hundred eighty-two thousand, six hundred fifty-nine".