2178423 has 24 divisors (see below), whose sum is σ = 3475472. Its totient is φ = 1306368.

The previous prime is 2178419. The next prime is 2178433. The reversal of 2178423 is 3248712.

It is not a de Polignac number, because 2178423 - 2² = 2178419 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

2178423 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4815 + ... + 5247.

2^2178423 is an apocalyptic number.

2178423 is a deficient number, since it is larger than the sum of its proper divisors (1297049).

2178423 is a wasteful number, since it uses less digits than its factorization.

2178423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495 (or 492 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 2178423 is about 1475.9481698217. The cubic root of 2178423 is about 129.6325521226.

It can be divided in two parts, 2178 and 423, that added together give a square (2601 = 51²).

The spelling of 2178423 in words is "two million, one hundred seventy-eight thousand, four hundred twenty-three".