1609820 has 12 divisors (see below), whose sum is σ = 3380664. Its totient is φ = 643920.

The previous prime is 1609807. The next prime is 1609843. The reversal of 1609820 is 289061.

1609820 = T₂₀₁ + T₂₀₂ + ... + T₂₆₀.

It is a self number, because there is not a number n which added to its sum of digits gives 1609820.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40226 + ... + 40265.

It is an arithmetic number, because the mean of its divisors is an integer number (281722).

2^1609820 is an apocalyptic number.

1609820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1609820 is an abundant number, since it is smaller than the sum of its proper divisors (1770844).

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

1609820 is a wasteful number, since it uses less digits than its factorization.

1609820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80500 (or 80498 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1609820 is about 1268.7868221258. The cubic root of 1609820 is about 117.1995037778.

The spelling of 1609820 in words is "one million, six hundred nine thousand, eight hundred twenty".