2643640 has 64 divisors (see below), whose sum is σ = 6415200. Its totient is φ = 978432.

The previous prime is 2643629. The next prime is 2643647. The reversal of 2643640 is 463462.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2643647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49854 + ... + 49906.

2^2643640 is an apocalyptic number.

2643640 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 2643640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3207600).

2643640 is an abundant number, since it is smaller than the sum of its proper divisors (3771560).

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

2643640 is a wasteful number, since it uses less digits than its factorization.

2643640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 2643640 is about 1625.9274276548. The cubic root of 2643640 is about 138.2719554809.

The spelling of 2643640 in words is "two million, six hundred forty-three thousand, six hundred forty".