1821997332 has 36 divisors (see below), whose sum is σ = 4616329536. Its totient is φ = 605918160.

The previous prime is 1821997273. The next prime is 1821997339. The reversal of 1821997332 is 2337991281.

1821997332 is a `hidden beast` number, since 18 + 219 + 97 + 332 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821997339) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43198 + ... + 74229.

It is an arithmetic number, because the mean of its divisors is an integer number (128231376).

Almost surely, 2^1821997332 is an apocalyptic number.

1821997332 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1821997332 is an abundant number, since it is smaller than the sum of its proper divisors (2794332204).

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

1821997332 is a wasteful number, since it uses less digits than its factorization.

1821997332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117868 (or 117863 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 1821997332 is about 42684.8606885392. The cubic root of 1821997332 is about 1221.3756166580.

The spelling of 1821997332 in words is "one billion, eight hundred twenty-one million, nine hundred ninety-seven thousand, three hundred thirty-two".