2091820 has 24 divisors (see below), whose sum is σ = 4501728. Its totient is φ = 816000.

The previous prime is 2091809. The next prime is 2091839. The reversal of 2091820 is 281902.

It is a junction number, because it is equal to n+sod(n) for n = 2091791 and 2091800.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 456 + ... + 2095.

It is an arithmetic number, because the mean of its divisors is an integer number (187572).

2^2091820 is an apocalyptic number.

2091820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2091820 is an abundant number, since it is smaller than the sum of its proper divisors (2409908).

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

2091820 is a wasteful number, since it uses less digits than its factorization.

2091820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2601 (or 2599 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 2091820 is about 1446.3125526663. The cubic root of 2091820 is about 127.8914281157.

The spelling of 2091820 in words is "two million, ninety-one thousand, eight hundred twenty".