2565640 has 128 divisors (see below), whose sum is σ = 7776000. Its totient is φ = 752640.

The previous prime is 2565611. The next prime is 2565643. The reversal of 2565640 is 465652.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 2565599 and 2565608.

It is not an unprimeable number, because it can be changed into a prime (2565643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 150912 + ... + 150928.

It is an arithmetic number, because the mean of its divisors is an integer number (60750).

2^2565640 is an apocalyptic number.

2565640 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 2565640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3888000).

2565640 is an abundant number, since it is smaller than the sum of its proper divisors (5210360).

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

2565640 is a wasteful number, since it uses less digits than its factorization.

2565640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 2565640 is about 1601.7615303159. The cubic root of 2565640 is about 136.8984631351.

The spelling of 2565640 in words is "two million, five hundred sixty-five thousand, six hundred forty".