2181256 has 32 divisors (see below), whose sum is σ = 5100480. Its totient is φ = 849600.

The previous prime is 2181247. The next prime is 2181259. The reversal of 2181256 is 6521812.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 2181256.

It is not an unprimeable number, because it can be changed into a prime (2181259) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1155 + ... + 2386.

It is an arithmetic number, because the mean of its divisors is an integer number (159390).

2^2181256 is an apocalyptic number.

It is an amenable number.

2181256 is an abundant number, since it is smaller than the sum of its proper divisors (2919224).

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

2181256 is a wasteful number, since it uses less digits than its factorization.

2181256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3565 (or 3561 counting only the distinct ones).

The product of its digits is 960, while the sum is 25.

The square root of 2181256 is about 1476.9075800469. The cubic root of 2181256 is about 129.6887227155.

The spelling of 2181256 in words is "two million, one hundred eighty-one thousand, two hundred fifty-six".