2556646 has 4 divisors (see below), whose sum is σ = 3834972. Its totient is φ = 1278322.

The previous prime is 2556641. The next prime is 2556661. The reversal of 2556646 is 6466552.

It is a semiprime because it is the product of two primes.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 639160 + ... + 639163.

It is an arithmetic number, because the mean of its divisors is an integer number (958743).

2^2556646 is an apocalyptic number.

2556646 is a deficient number, since it is larger than the sum of its proper divisors (1278326).

2556646 is a wasteful number, since it uses less digits than its factorization.

2556646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1278325.

The product of its digits is 43200, while the sum is 34.

The square root of 2556646 is about 1598.9515314730. The cubic root of 2556646 is about 136.7383073399.

The spelling of 2556646 in words is "two million, five hundred fifty-six thousand, six hundred forty-six".