2181888 has 54 divisors (see below), whose sum is σ = 6297564. Its totient is φ = 726528.

The previous prime is 2181871. The next prime is 2181889. The reversal of 2181888 is 8881812.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (2181889) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1831 + ... + 2777.

2^2181888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2181888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3148782).

2181888 is an abundant number, since it is smaller than the sum of its proper divisors (4115676).

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

2181888 is an equidigital number, since it uses as much as digits as its factorization.

2181888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 969 (or 952 counting only the distinct ones).

The product of its digits is 8192, while the sum is 36.

The square root of 2181888 is about 1477.1215251292. The cubic root of 2181888 is about 129.7012469001.

The spelling of 2181888 in words is "two million, one hundred eighty-one thousand, eight hundred eighty-eight".