2555640 has 96 divisors (see below), whose sum is σ = 8611200. Its totient is φ = 656640.

The previous prime is 2555639. The next prime is 2555647. The reversal of 2555640 is 465552.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2555647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11046 + ... + 11274.

It is an arithmetic number, because the mean of its divisors is an integer number (89700).

2^2555640 is an apocalyptic number.

2555640 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 2555640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4305600).

2555640 is an abundant number, since it is smaller than the sum of its proper divisors (6055560).

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

2555640 is a wasteful number, since it uses less digits than its factorization.

2555640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The square root of 2555640 is about 1598.6369193785. The cubic root of 2555640 is about 136.7203701958.

The spelling of 2555640 in words is "two million, five hundred fifty-five thousand, six hundred forty".