2540640 has 96 divisors (see below), whose sum is σ = 8225280. Its totient is φ = 658944.

The previous prime is 2540627. The next prime is 2540641. The reversal of 2540640 is 460452.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2540641) 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, 32121 + ... + 32199.

It is an arithmetic number, because the mean of its divisors is an integer number (85680).

2^2540640 is an apocalyptic number.

2540640 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 2540640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4112640).

2540640 is an abundant number, since it is smaller than the sum of its proper divisors (5684640).

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

2540640 is a wasteful number, since it uses less digits than its factorization.

2540640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 2540640 is about 1593.9385182622. The cubic root of 2540640 is about 136.4523576170.

The spelling of 2540640 in words is "two million, five hundred forty thousand, six hundred forty".