1990818 has 20 divisors (see below), whose sum is σ = 4461270. Its totient is φ = 663552.

The previous prime is 1990787. The next prime is 1990823. The reversal of 1990818 is 8180991.

It can be written as a sum of positive squares in only one way, i.e., 1432809 + 558009 = 1197^2 + 747^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 5983 + ... + 6306.

2^1990818 is an apocalyptic number.

1990818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1990818 is an abundant number, since it is smaller than the sum of its proper divisors (2470452).

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

1990818 is a wasteful number, since it uses less digits than its factorization.

1990818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12303 (or 12294 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 1990818 is about 1410.9635005910. The cubic root of 1990818 is about 125.7989992532.

The spelling of 1990818 in words is "one million, nine hundred ninety thousand, eight hundred eighteen".