2644893864 has 128 divisors (see below), whose sum is σ = 7798032000. Its totient is φ = 827753472.

The previous prime is 2644893863. The next prime is 2644893869. The reversal of 2644893864 is 4683984462.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 2644893864.

It is not an unprimeable number, because it can be changed into a prime (2644893863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2419302 + ... + 2420394.

It is an arithmetic number, because the mean of its divisors is an integer number (60922125).

Almost surely, 2^2644893864 is an apocalyptic number.

2644893864 is a gapful number since it is divisible by the number (24) 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 2644893864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3899016000).

2644893864 is an abundant number, since it is smaller than the sum of its proper divisors (5153138136).

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

2644893864 is a wasteful number, since it uses less digits than its factorization.

2644893864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1784 (or 1774 counting only the distinct ones).

The product of its digits is 7962624, while the sum is 54.

The square root of 2644893864 is about 51428.5316142703. The cubic root of 2644893864 is about 1382.9381256991.

The spelling of 2644893864 in words is "two billion, six hundred forty-four million, eight hundred ninety-three thousand, eight hundred sixty-four".