1821312732 has 48 divisors (see below), whose sum is σ = 4358188800. Its totient is φ = 591803520.

The previous prime is 1821312667. The next prime is 1821312733. The reversal of 1821312732 is 2372131281.

It is a self number, because there is not a number n which added to its sum of digits gives 1821312732.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821312733) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63819 + ... + 87837.

It is an arithmetic number, because the mean of its divisors is an integer number (90795600).

Almost surely, 2^1821312732 is an apocalyptic number.

1821312732 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1821312732 is an abundant number, since it is smaller than the sum of its proper divisors (2536876068).

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

1821312732 is a wasteful number, since it uses less digits than its factorization.

1821312732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24186 (or 24184 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 1821312732 is about 42676.8406984397. The cubic root of 1821312732 is about 1221.2226236614. Note that the first 3 decimals are identical.

The spelling of 1821312732 in words is "one billion, eight hundred twenty-one million, three hundred twelve thousand, seven hundred thirty-two".