2181788 has 24 divisors (see below), whose sum is σ = 4432512. Its totient is φ = 920304.

The previous prime is 2181737. The next prime is 2181833. The reversal of 2181788 is 8871812.

2181788 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1295 + ... + 2457.

It is an arithmetic number, because the mean of its divisors is an integer number (184688).

2^2181788 is an apocalyptic number.

2181788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

2181788 is an abundant number, since it is smaller than the sum of its proper divisors (2250724).

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

2181788 is a wasteful number, since it uses less digits than its factorization.

2181788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241 (or 1239 counting only the distinct ones).

The product of its digits is 7168, while the sum is 35.

The square root of 2181788 is about 1477.0876751229. The cubic root of 2181788 is about 129.6992653864.

The spelling of 2181788 in words is "two million, one hundred eighty-one thousand, seven hundred eighty-eight".