639552789 has 12 divisors (see below), whose sum is σ = 963963936. Its totient is φ = 407830632.

The previous prime is 639552779. The next prime is 639552791. The reversal of 639552789 is 987255936.

639552789 is a `hidden beast` number, since 6 + 3 + 9 + 552 + 7 + 89 = 666.

639552789 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 639552789 - 2⁵ = 639552757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639552709) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1544607 + ... + 1545020.

It is an arithmetic number, because the mean of its divisors is an integer number (80330328).

Almost surely, 2^639552789 is an apocalyptic number.

639552789 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

It is an amenable number.

639552789 is a deficient number, since it is larger than the sum of its proper divisors (324411147).

639552789 is a wasteful number, since it uses less digits than its factorization.

639552789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3089656 (or 3089653 counting only the distinct ones).

The product of its digits is 4082400, while the sum is 54.

The square root of 639552789 is about 25289.3809532776. The cubic root of 639552789 is about 861.5731028050.

The spelling of 639552789 in words is "six hundred thirty-nine million, five hundred fifty-two thousand, seven hundred eighty-nine".