2157420 has 48 divisors (see below), whose sum is σ = 6195168. Its totient is φ = 560640.

The previous prime is 2157413. The next prime is 2157427. The reversal of 2157420 is 247512.

2157420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2157413) and next prime (2157427).

It is a super-2 number, since 2×2157420² = 9308922112800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2157427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2022 + ... + 2898.

It is an arithmetic number, because the mean of its divisors is an integer number (129066).

2^2157420 is an apocalyptic number.

2157420 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 2157420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3097584).

2157420 is an abundant number, since it is smaller than the sum of its proper divisors (4037748).

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

2157420 is a wasteful number, since it uses less digits than its factorization.

2157420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930 (or 928 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 2157420 is about 1468.8158495877. The cubic root of 2157420 is about 129.2145938459.

The spelling of 2157420 in words is "two million, one hundred fifty-seven thousand, four hundred twenty".