1821409440 has 96 divisors (see below), whose sum is σ = 5761808640. Its totient is φ = 483646464.

The previous prime is 1821409439. The next prime is 1821409451. The reversal of 1821409440 is 449041281.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×1821409440² = 6635064696242227200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106782 + ... + 122658.

It is an arithmetic number, because the mean of its divisors is an integer number (60018840).

Almost surely, 2^1821409440 is an apocalyptic number.

1821409440 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 1821409440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2880904320).

1821409440 is an abundant number, since it is smaller than the sum of its proper divisors (3940399200).

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

1821409440 is a wasteful number, since it uses less digits than its factorization.

1821409440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16134 (or 16126 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 1821409440 is about 42677.9737101002. The cubic root of 1821409440 is about 1221.2442380910.

The spelling of 1821409440 in words is "one billion, eight hundred twenty-one million, four hundred nine thousand, four hundred forty".