2556644 has 12 divisors (see below), whose sum is σ = 4489968. Its totient is φ = 1273800.

The previous prime is 2556641. The next prime is 2556661. The reversal of 2556644 is 4466552.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 2556644.

It is not an unprimeable number, because it can be changed into a prime (2556641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359 + ... + 2289.

It is an arithmetic number, because the mean of its divisors is an integer number (374164).

2^2556644 is an apocalyptic number.

It is an amenable number.

2556644 is a deficient number, since it is larger than the sum of its proper divisors (1933324).

2556644 is a wasteful number, since it uses less digits than its factorization.

2556644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2266 (or 2264 counting only the distinct ones).

The product of its digits is 28800, while the sum is 32.

The square root of 2556644 is about 1598.9509060631. The cubic root of 2556644 is about 136.7382716843.

It can be divided in two parts, 25 and 56644, that multiplied together give a square (1416100 = 1190²).

The spelling of 2556644 in words is "two million, five hundred fifty-six thousand, six hundred forty-four".