2688240 has 80 divisors (see below), whose sum is σ = 8713728. Its totient is φ = 684288.

The previous prime is 2688239. The next prime is 2688299. The reversal of 2688240 is 428862.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 2688198 and 2688207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5277 + ... + 5763.

2^2688240 is an apocalyptic number.

2688240 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 2688240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4356864).

2688240 is an abundant number, since it is smaller than the sum of its proper divisors (6025488).

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

2688240 is a wasteful number, since it uses less digits than its factorization.

2688240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526 (or 520 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 2688240 is about 1639.5853134253. The cubic root of 2688240 is about 139.0452037993.

The spelling of 2688240 in words is "two million, six hundred eighty-eight thousand, two hundred forty".