2639981639 has 8 divisors (see below), whose sum is σ = 2670919680. Its totient is φ = 2609202456.

The previous prime is 2639981599. The next prime is 2639981651. The reversal of 2639981639 is 9361899362.

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 2639981639 - 2²⁸ = 2371546183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2639980639) 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, 6119 + ... + 72920.

It is an arithmetic number, because the mean of its divisors is an integer number (333864960).

Almost surely, 2^2639981639 is an apocalyptic number.

2639981639 is a deficient number, since it is larger than the sum of its proper divisors (30938041).

2639981639 is a wasteful number, since it uses less digits than its factorization.

2639981639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79429.

The product of its digits is 3779136, while the sum is 56.

The square root of 2639981639 is about 51380.7516391109. The cubic root of 2639981639 is about 1382.0814418968.

The spelling of 2639981639 in words is "two billion, six hundred thirty-nine million, nine hundred eighty-one thousand, six hundred thirty-nine".