1820845141021 has 4 divisors (see below), whose sum is σ = 1821236809500. Its totient is φ = 1820453472544.

The previous prime is 1820845140931. The next prime is 1820845141039. The reversal of 1820845141021 is 1201415480281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1310029039225 + 510816101796 = 1144565^2 + 714714^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820845141021 - 2⁷ = 1820845140893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820845141091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195827266 + ... + 195836563.

It is an arithmetic number, because the mean of its divisors is an integer number (455309202375).

Almost surely, 2^{1820845141021} is an apocalyptic number.

It is an amenable number.

1820845141021 is a deficient number, since it is larger than the sum of its proper divisors (391668479).

1820845141021 is an equidigital number, since it uses as much as digits as its factorization.

1820845141021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391668478.

The product of its (nonzero) digits is 20480, while the sum is 37.

The spelling of 1820845141021 in words is "one trillion, eight hundred twenty billion, eight hundred forty-five million, one hundred forty-one thousand, twenty-one".