2561544 has 80 divisors (see below), whose sum is σ = 7405200. Its totient is φ = 826848.

The previous prime is 2561527. The next prime is 2561549. The reversal of 2561544 is 4451652.

2561544 is a `hidden beast` number, since 2 + 5 + 615 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2561549) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 38199 + ... + 38265.

It is an arithmetic number, because the mean of its divisors is an integer number (92565).

2^2561544 is an apocalyptic number.

2561544 is a gapful number since it is divisible by the number (24) 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 2561544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3702600).

2561544 is an abundant number, since it is smaller than the sum of its proper divisors (4843656).

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

2561544 is a wasteful number, since it uses less digits than its factorization.

2561544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 131 counting only the distinct ones).

The product of its digits is 4800, while the sum is 27.

The square root of 2561544 is about 1600.4824272700. The cubic root of 2561544 is about 136.8255723201.

The spelling of 2561544 in words is "two million, five hundred sixty-one thousand, five hundred forty-four".