2644281640 has 128 divisors (see below), whose sum is σ = 7988440320. Its totient is φ = 760780800.

The previous prime is 2644281587. The next prime is 2644281721. The reversal of 2644281640 is 461824462.

It is a happy number.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 2644281640.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7020 + ... + 73060.

It is an arithmetic number, because the mean of its divisors is an integer number (62409690).

Almost surely, 2^2644281640 is an apocalyptic number.

2644281640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2644281640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3994220160).

2644281640 is an abundant number, since it is smaller than the sum of its proper divisors (5344158680).

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

2644281640 is a wasteful number, since it uses less digits than its factorization.

2644281640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66083 (or 66079 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 37.

The square root of 2644281640 is about 51422.5790874009. The cubic root of 2644281640 is about 1382.8314127533.

The spelling of 2644281640 in words is "two billion, six hundred forty-four million, two hundred eighty-one thousand, six hundred forty".