2609640 has 96 divisors (see below), whose sum is σ = 9266400. Its totient is φ = 631680.

The previous prime is 2609639. The next prime is 2609657. The reversal of 2609640 is 469062.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3631 + ... + 4289.

It is an arithmetic number, because the mean of its divisors is an integer number (96525).

2^2609640 is an apocalyptic number.

2609640 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 2609640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4633200).

2609640 is an abundant number, since it is smaller than the sum of its proper divisors (6656760).

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

2609640 is a wasteful number, since it uses less digits than its factorization.

2609640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687 (or 680 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 2609640 is about 1615.4380210952. The cubic root of 2609640 is about 137.6766215138.

It can be divided in two parts, 2609 and 640, that added together give a square (3249 = 57²).

The spelling of 2609640 in words is "two million, six hundred nine thousand, six hundred forty".