2644240 has 20 divisors (see below), whose sum is σ = 6148044. Its totient is φ = 1057664.

The previous prime is 2644219. The next prime is 2644247. The reversal of 2644240 is 424462.

It can be written as a sum of positive squares in 2 ways, for example, as 1628176 + 1016064 = 1276^2 + 1008^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a d-powerful number, because it can be written as 2¹⁹ + 6⁴ + 4⁵ + 4⁶ + 2²¹ + 4⁷ + 0 .

It is not an unprimeable number, because it can be changed into a prime (2644247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16447 + ... + 16606.

2^2644240 is an apocalyptic number.

2644240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2644240 is an abundant number, since it is smaller than the sum of its proper divisors (3503804).

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

2644240 is a wasteful number, since it uses less digits than its factorization.

2644240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33066 (or 33060 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 2644240 is about 1626.1119272670. Note that the first 3 decimals coincide. The cubic root of 2644240 is about 138.2824154147.

The spelling of 2644240 in words is "two million, six hundred forty-four thousand, two hundred forty".