1821493806920 has 32 divisors (see below), whose sum is σ = 4107488859000. Its totient is φ = 726974803968.

The previous prime is 1821493806883. The next prime is 1821493806941. The reversal of 1821493806920 is 296083941281.

It can be written as a sum of positive squares in 4 ways, for example, as 1115588013796 + 705905793124 = 1056214^2 + 840182^2 .

It is a super-3 number, since 3×1821493806920³ (a number of 38 digits) contains 333 as substring.

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, 50691779 + ... + 50727698.

Almost surely, 2^{1821493806920} is an apocalyptic number.

1821493806920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821493806920 is an abundant number, since it is smaller than the sum of its proper divisors (2285995052080).

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

1821493806920 is a wasteful number, since it uses less digits than its factorization.

1821493806920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101419937 (or 101419933 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 53.

The spelling of 1821493806920 in words is "one trillion, eight hundred twenty-one billion, four hundred ninety-three million, eight hundred six thousand, nine hundred twenty".