2178189 has 12 divisors (see below), whose sum is σ = 3388476. Its totient is φ = 1340352.

The previous prime is 2178173. The next prime is 2178191. The reversal of 2178189 is 9818712.

It can be written as a sum of positive squares in 2 ways, for example, as 1340964 + 837225 = 1158^2 + 915^2 .

It is not a de Polignac number, because 2178189 - 2⁴ = 2178173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178139) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9192 + ... + 9425.

It is an arithmetic number, because the mean of its divisors is an integer number (282373).

2^2178189 is an apocalyptic number.

It is an amenable number.

2178189 is a deficient number, since it is larger than the sum of its proper divisors (1210287).

2178189 is a wasteful number, since it uses less digits than its factorization.

2178189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18636 (or 18633 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 2178189 is about 1475.8688966165. The cubic root of 2178189 is about 129.6279103697.

It can be divided in two parts, 21 and 78189, that added together give a triangular number (78210 = T₃₉₅).

The spelling of 2178189 in words is "two million, one hundred seventy-eight thousand, one hundred eighty-nine".