1800020988 has 48 divisors (see below), whose sum is σ = 4672702720. Its totient is φ = 599238000.

The previous prime is 1800020977. The next prime is 1800021007. The reversal of 1800020988 is 8890200081.

It is a super-2 number, since 2×1800020988² = 6480151114480992288, which contains 22 as substring.

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 a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77313 + ... + 97863.

Almost surely, 2^1800020988 is an apocalyptic number.

1800020988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1800020988 is an abundant number, since it is smaller than the sum of its proper divisors (2872681732).

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

1800020988 is a wasteful number, since it uses less digits than its factorization.

1800020988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21375 (or 21367 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 1800020988 is about 42426.6542164239. The cubic root of 1800020988 is about 1216.4451269947.

The spelling of 1800020988 in words is "one billion, eight hundred million, twenty thousand, nine hundred eighty-eight".