639465859 has 4 divisors (see below), whose sum is σ = 640137816. Its totient is φ = 638793904.

The previous prime is 639465847. The next prime is 639465877. The reversal of 639465859 is 958564936.

639465859 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 639465859 - 2⁷ = 639465731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639465809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 334549 + ... + 336454.

It is an arithmetic number, because the mean of its divisors is an integer number (160034454).

Almost surely, 2^639465859 is an apocalyptic number.

639465859 is a deficient number, since it is larger than the sum of its proper divisors (671957).

639465859 is an equidigital number, since it uses as much as digits as its factorization.

639465859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671956.

The product of its digits is 6998400, while the sum is 55.

The square root of 639465859 is about 25287.6621892970. The cubic root of 639465859 is about 861.5340651396.

The spelling of 639465859 in words is "six hundred thirty-nine million, four hundred sixty-five thousand, eight hundred fifty-nine".