639430909797 has 16 divisors (see below), whose sum is σ = 875729796480. Its totient is φ = 414712613952.

The previous prime is 639430909687. The next prime is 639430909801. The reversal of 639430909797 is 797909034936.

639430909797 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 639430909797 - 2²³ = 639422521189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639430902797) 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, 504904 + ... + 1238462.

It is an arithmetic number, because the mean of its divisors is an integer number (54733112280).

Almost surely, 2^639430909797 is an apocalyptic number.

It is an amenable number.

639430909797 is a deficient number, since it is larger than the sum of its proper divisors (236298886683).

639430909797 is a wasteful number, since it uses less digits than its factorization.

639430909797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 741452.

The product of its (nonzero) digits is 69441624, while the sum is 66.

The spelling of 639430909797 in words is "six hundred thirty-nine billion, four hundred thirty million, nine hundred nine thousand, seven hundred ninety-seven".