639850345 has 16 divisors (see below), whose sum is σ = 795105360. Its totient is φ = 493726464.

The previous prime is 639850331. The next prime is 639850349. The reversal of 639850345 is 543058936.

639850345 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 119508624 + 520341721 = 10932^2 + 22811^2 .

It is a cyclic number.

It is not a de Polignac number, because 639850345 - 2⁷ = 639850217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639850349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209167 + ... + 212203.

It is an arithmetic number, because the mean of its divisors is an integer number (49694085).

Almost surely, 2^639850345 is an apocalyptic number.

It is an amenable number.

639850345 is a deficient number, since it is larger than the sum of its proper divisors (155255015).

639850345 is a wasteful number, since it uses less digits than its factorization.

639850345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4524.

The product of its (nonzero) digits is 388800, while the sum is 43.

The square root of 639850345 is about 25295.2632917707. The cubic root of 639850345 is about 861.7066995423.

The spelling of 639850345 in words is "six hundred thirty-nine million, eight hundred fifty thousand, three hundred forty-five".