2145820 has 24 divisors (see below), whose sum is σ = 4652928. Its totient is φ = 830400.

The previous prime is 2145779. The next prime is 2145821. The reversal of 2145820 is 285412.

It is a junction number, because it is equal to n+sod(n) for n = 2145791 and 2145800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145821) 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, 1111 + ... + 2350.

It is an arithmetic number, because the mean of its divisors is an integer number (193872).

2^2145820 is an apocalyptic number.

2145820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2145820 is an abundant number, since it is smaller than the sum of its proper divisors (2507108).

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

2145820 is a wasteful number, since it uses less digits than its factorization.

2145820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3501 (or 3499 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 2145820 is about 1464.8617682225. The cubic root of 2145820 is about 128.9825908442.

The spelling of 2145820 in words is "two million, one hundred forty-five thousand, eight hundred twenty".