181820000020 has 24 divisors (see below), whose sum is σ = 385602420168. Its totient is φ = 72007920000.

The previous prime is 181820000003. The next prime is 181820000069. The reversal of 181820000020 is 20000028181.

It can be written as a sum of positive squares in 4 ways, for example, as 24366585604 + 157453414416 = 156098^2 + 396804^2 .

It is a junction number, because it is equal to n+sod(n) for n = 181819999946 and 181820000000.

It is a congruent number.

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, 45002931 + ... + 45006970.

It is an arithmetic number, because the mean of its divisors is an integer number (16066767507).

Almost surely, 2^181820000020 is an apocalyptic number.

181820000020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181820000020 is an abundant number, since it is smaller than the sum of its proper divisors (203782420148).

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

181820000020 is a wasteful number, since it uses less digits than its factorization.

181820000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90010011 (or 90010009 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 22.

The spelling of 181820000020 in words is "one hundred eighty-one billion, eight hundred twenty million, twenty", and thus it is an aban number.