1820000020 has 24 divisors (see below), whose sum is σ = 3828470184. Its totient is φ = 726767616.

The previous prime is 1820000003. The next prime is 1820000033. The reversal of 1820000020 is 200000281.

It can be written as a sum of positive squares in 4 ways, for example, as 775288336 + 1044711684 = 27844^2 + 32322^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64869 + ... + 88588.

It is an arithmetic number, because the mean of its divisors is an integer number (159519591).

Almost surely, 2^1820000020 is an apocalyptic number.

1820000020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820000020 is an abundant number, since it is smaller than the sum of its proper divisors (2008470164).

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

1820000020 is a wasteful number, since it uses less digits than its factorization.

1820000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154059 (or 154057 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1820000020 is about 42661.4582498067. The cubic root of 1820000020 is about 1220.9291542191.

The spelling of 1820000020 in words is "one billion, eight hundred twenty million, twenty", and thus it is an aban number.