639649265847 has 8 divisors (see below), whose sum is σ = 852869470320. Its totient is φ = 426430952640.

The previous prime is 639649265839. The next prime is 639649265891. The reversal of 639649265847 is 748562946936.

639649265847 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 639649265847 - 2³ = 639649265839 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639649265837) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 826179 + ... + 1400667.

It is an arithmetic number, because the mean of its divisors is an integer number (106608683790).

Almost surely, 2^639649265847 is an apocalyptic number.

639649265847 is a deficient number, since it is larger than the sum of its proper divisors (213220204473).

639649265847 is a wasteful number, since it uses less digits than its factorization.

639649265847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 945633.

The product of its digits is 470292480, while the sum is 69.

The spelling of 639649265847 in words is "six hundred thirty-nine billion, six hundred forty-nine million, two hundred sixty-five thousand, eight hundred forty-seven".