1820020321 has 8 divisors (see below), whose sum is σ = 2083388480. Its totient is φ = 1557493488.

The previous prime is 1820020297. The next prime is 1820020331. The reversal of 1820020321 is 1230200281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1820020321 - 2¹⁵ = 1819987553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1820020331) 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, 205686 + ... + 214351.

It is an arithmetic number, because the mean of its divisors is an integer number (260423560).

Almost surely, 2^1820020321 is an apocalyptic number.

It is an amenable number.

1820020321 is a deficient number, since it is larger than the sum of its proper divisors (263368159).

1820020321 is an equidigital number, since it uses as much as digits as its factorization.

1820020321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420663.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 1820020321 is about 42661.6961805318. The cubic root of 1820020321 is about 1220.9336937777.

The spelling of 1820020321 in words is "one billion, eight hundred twenty million, twenty thousand, three hundred twenty-one".