2181389 has 16 divisors (see below), whose sum is σ = 2757888. Its totient is φ = 1681152.

The previous prime is 2181379. The next prime is 2181419. The reversal of 2181389 is 9831812.

It is a cyclic number.

It is not a de Polignac number, because 2181389 - 2⁴ = 2181373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2339 + ... + 3135.

It is an arithmetic number, because the mean of its divisors is an integer number (172368).

2^2181389 is an apocalyptic number.

It is an amenable number.

2181389 is a deficient number, since it is larger than the sum of its proper divisors (576499).

2181389 is a wasteful number, since it uses less digits than its factorization.

2181389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844.

The product of its digits is 3456, while the sum is 32.

The square root of 2181389 is about 1476.9526058747. The cubic root of 2181389 is about 129.6913585439.

The spelling of 2181389 in words is "two million, one hundred eighty-one thousand, three hundred eighty-nine".