18190820 has 12 divisors (see below), whose sum is σ = 38200764. Its totient is φ = 7276320.

The previous prime is 18190811. The next prime is 18190841. The reversal of 18190820 is 2809181.

It can be written as a sum of positive squares in 2 ways, for example, as 7706176 + 10484644 = 2776^2 + 3238^2 .

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 454751 + ... + 454790.

It is an arithmetic number, because the mean of its divisors is an integer number (3183397).

Almost surely, 2^18190820 is an apocalyptic number.

18190820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18190820 is an abundant number, since it is smaller than the sum of its proper divisors (20009944).

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

18190820 is a wasteful number, since it uses less digits than its factorization.

18190820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909550 (or 909548 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 18190820 is about 4265.0697532397. The cubic root of 18190820 is about 262.9969783805.

The spelling of 18190820 in words is "eighteen million, one hundred ninety thousand, eight hundred twenty".