1821238660 has 12 divisors (see below), whose sum is σ = 3824601228. Its totient is φ = 728495456.

The previous prime is 1821238637. The next prime is 1821238663. The reversal of 1821238660 is 668321281.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 360164484 + 1461074176 = 18978^2 + 38224^2 .

It is not an unprimeable number, because it can be changed into a prime (1821238663) 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, 45530947 + ... + 45530986.

It is an arithmetic number, because the mean of its divisors is an integer number (318716769).

Almost surely, 2^1821238660 is an apocalyptic number.

1821238660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821238660 is an abundant number, since it is smaller than the sum of its proper divisors (2003362568).

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

1821238660 is a wasteful number, since it uses less digits than its factorization.

1821238660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91061942 (or 91061940 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 1821238660 is about 42675.9728653021. The cubic root of 1821238660 is about 1221.2060679052.

The spelling of 1821238660 in words is "one billion, eight hundred twenty-one million, two hundred thirty-eight thousand, six hundred sixty".