639854641 has 8 divisors (see below), whose sum is σ = 667992960. Its totient is φ = 611742912.

The previous prime is 639854561. The next prime is 639854647. The reversal of 639854641 is 146458936.

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

It is a cyclic number.

It is not a de Polignac number, because 639854641 - 2¹⁵ = 639821873 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639854591 and 639854600.

It is not an unprimeable number, because it can be changed into a prime (639854647) 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, 54676 + ... + 65338.

It is an arithmetic number, because the mean of its divisors is an integer number (83499120).

Almost surely, 2^639854641 is an apocalyptic number.

It is an amenable number.

639854641 is a deficient number, since it is larger than the sum of its proper divisors (28138319).

639854641 is a wasteful number, since it uses less digits than its factorization.

639854641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13295.

The product of its digits is 622080, while the sum is 46.

The square root of 639854641 is about 25295.3482087122. The cubic root of 639854641 is about 861.7086280577.

The spelling of 639854641 in words is "six hundred thirty-nine million, eight hundred fifty-four thousand, six hundred forty-one".