639425649 has 16 divisors (see below), whose sum is σ = 862723008. Its totient is φ = 421220352.

The previous prime is 639425629. The next prime is 639425671. The reversal of 639425649 is 946524936.

639425649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 639425649 - 2⁵ = 639425617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 639425598 and 639425607.

It is not an unprimeable number, because it can be changed into a prime (639425629) 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, 239329 + ... + 241985.

It is an arithmetic number, because the mean of its divisors is an integer number (53920188).

Almost surely, 2^639425649 is an apocalyptic number.

It is an amenable number.

639425649 is a deficient number, since it is larger than the sum of its proper divisors (223297359).

639425649 is a wasteful number, since it uses less digits than its factorization.

639425649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3584.

The product of its digits is 1399680, while the sum is 48.

The square root of 639425649 is about 25286.8671250513. The cubic root of 639425649 is about 861.5160068334.

The spelling of 639425649 in words is "six hundred thirty-nine million, four hundred twenty-five thousand, six hundred forty-nine".