2181144 has 32 divisors (see below), whose sum is σ = 6232320. Its totient is φ = 623136.

The previous prime is 2181139. The next prime is 2181149. The reversal of 2181144 is 4411812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2181139) and next prime (2181149).

It is a Harshad number since it is a multiple of its sum of digits (21).

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

It is a self number, because there is not a number n which added to its sum of digits gives 2181144.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181149) 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, 6324 + ... + 6659.

It is an arithmetic number, because the mean of its divisors is an integer number (194760).

2^2181144 is an apocalyptic number.

2181144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

2181144 is an abundant number, since it is smaller than the sum of its proper divisors (4051176).

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

2181144 is a wasteful number, since it uses less digits than its factorization.

2181144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12999 (or 12995 counting only the distinct ones).

The product of its digits is 256, while the sum is 21.

The square root of 2181144 is about 1476.8696624956. The cubic root of 2181144 is about 129.6865029874.

Adding to 2181144 its reverse (4411812), we get a palindrome (6592956).

The spelling of 2181144 in words is "two million, one hundred eighty-one thousand, one hundred forty-four".