2639999964 has 96 divisors (see below), whose sum is σ = 7357464576. Its totient is φ = 721022400.

The previous prime is 2639999951. The next prime is 2639999981. The reversal of 2639999964 is 4699999362.

It is a junction number, because it is equal to n+sod(n) for n = 2639999895 and 2639999904.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 161989 + ... + 177539.

It is an arithmetic number, because the mean of its divisors is an integer number (76640256).

Almost surely, 2^2639999964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2639999964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3678732288).

2639999964 is an abundant number, since it is smaller than the sum of its proper divisors (4717464612).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2639999964 is a wasteful number, since it uses less digits than its factorization.

2639999964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15655 (or 15653 counting only the distinct ones).

The product of its digits is 51018336, while the sum is 66.

The square root of 2639999964 is about 51380.9299643360. The cubic root of 2639999964 is about 1382.0846397200.

The spelling of 2639999964 in words is "two billion, six hundred thirty-nine million, nine hundred ninety-nine thousand, nine hundred sixty-four".