2640240 has 120 divisors (see below), whose sum is σ = 9381840. Its totient is φ = 663552.

The previous prime is 2640227. The next prime is 2640251. The reversal of 2640240 is 420462.

2640240 is a `hidden beast` number, since 2 + 640 + 24 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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, 13584 + ... + 13776.

It is an arithmetic number, because the mean of its divisors is an integer number (78182).

2^2640240 is an apocalyptic number.

2640240 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 2640240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4690920).

2640240 is an abundant number, since it is smaller than the sum of its proper divisors (6741600).

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

2640240 is a wasteful number, since it uses less digits than its factorization.

2640240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231 (or 222 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 2640240 is about 1624.8815341433. The cubic root of 2640240 is about 138.2126526086.

The spelling of 2640240 in words is "two million, six hundred forty thousand, two hundred forty".