2639921968 has 40 divisors (see below), whose sum is σ = 5521298400. Its totient is φ = 1219029504.

The previous prime is 2639921957. The next prime is 2639921969. The reversal of 2639921968 is 8691299362.

It is a happy number.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (2639921969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113013 + ... + 134356.

It is an arithmetic number, because the mean of its divisors is an integer number (138032460).

Almost surely, 2^2639921968 is an apocalyptic number.

It is an amenable number.

2639921968 is an abundant number, since it is smaller than the sum of its proper divisors (2881376432).

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

2639921968 is a wasteful number, since it uses less digits than its factorization.

2639921968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247429 (or 247423 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 55.

The square root of 2639921968 is about 51380.1709611792. The cubic root of 2639921968 is about 1382.0710288442.

The spelling of 2639921968 in words is "two billion, six hundred thirty-nine million, nine hundred twenty-one thousand, nine hundred sixty-eight".