2178220 has 24 divisors (see below), whose sum is σ = 4990608. Its totient is φ = 792000.

The previous prime is 2178203. The next prime is 2178223. The reversal of 2178220 is 228712.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 2178191 and 2178200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178223) 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, 4731 + ... + 5170.

It is an arithmetic number, because the mean of its divisors is an integer number (207942).

2^2178220 is an apocalyptic number.

2178220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2178220 is an abundant number, since it is smaller than the sum of its proper divisors (2812388).

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

2178220 is a wasteful number, since it uses less digits than its factorization.

2178220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9921 (or 9919 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 2178220 is about 1475.8793988670. The cubic root of 2178220 is about 129.6285253219.

The spelling of 2178220 in words is "two million, one hundred seventy-eight thousand, two hundred twenty".