1821640800 has 288 divisors, whose sum is σ = 7012051200. Its totient is φ = 401909760.

The previous prime is 1821640741. The next prime is 1821640811. The reversal of 1821640800 is 80461281.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 485331 + ... + 489069.

It is an arithmetic number, because the mean of its divisors is an integer number (24347400).

Almost surely, 2^1821640800 is an apocalyptic number.

1821640800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1821640800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3506025600).

1821640800 is an abundant number, since it is smaller than the sum of its proper divisors (5190410400).

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

1821640800 is a wasteful number, since it uses less digits than its factorization.

1821640800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3798 (or 3785 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 1821640800 is about 42680.6841557162. The cubic root of 1821640800 is about 1221.2959444048.

The spelling of 1821640800 in words is "one billion, eight hundred twenty-one million, six hundred forty thousand, eight hundred".