1820004020 has 24 divisors (see below), whose sum is σ = 4046833224. Its totient is φ = 685177856.

The previous prime is 1820003993. The next prime is 1820004023. The reversal of 1820004020 is 204000281.

It can be written as a sum of positive squares in 4 ways, for example, as 705646096 + 1114357924 = 26564^2 + 33382^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 1820004020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820004023) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2676137 + ... + 2676816.

It is an arithmetic number, because the mean of its divisors is an integer number (168618051).

Almost surely, 2^1820004020 is an apocalyptic number.

1820004020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820004020 is an abundant number, since it is smaller than the sum of its proper divisors (2226829204).

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

1820004020 is a wasteful number, since it uses less digits than its factorization.

1820004020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5352979 (or 5352977 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 1820004020 is about 42661.5051305038. The cubic root of 1820004020 is about 1220.9300486720.

The spelling of 1820004020 in words is "one billion, eight hundred twenty million, four thousand, twenty".