2156420 has 48 divisors (see below), whose sum is σ = 5271168. Its totient is φ = 725760.

The previous prime is 2156417. The next prime is 2156437. The reversal of 2156420 is 246512.

2156420 = 70² + 71² + ... + 189².

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 2156392 and 2156401.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10115 + ... + 10325.

It is an arithmetic number, because the mean of its divisors is an integer number (109816).

2^2156420 is an apocalyptic number.

2156420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2156420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2635584).

2156420 is an abundant number, since it is smaller than the sum of its proper divisors (3114748).

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

2156420 is a wasteful number, since it uses less digits than its factorization.

2156420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 298 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 2156420 is about 1468.4753998620. The cubic root of 2156420 is about 129.1946263904.

The spelling of 2156420 in words is "two million, one hundred fifty-six thousand, four hundred twenty".