21846320 has 80 divisors (see below), whose sum is σ = 54853632. Its totient is φ = 8067840.

The previous prime is 21846311. The next prime is 21846323. The reversal of 21846320 is 2364812.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 21846320.

It is not an unprimeable number, because it can be changed into a prime (21846323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56849 + ... + 57231.

Almost surely, 2^21846320 is an apocalyptic number.

21846320 is a gapful number since it is divisible by the number (20) 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 21846320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27426816).

21846320 is an abundant number, since it is smaller than the sum of its proper divisors (33007312).

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

21846320 is a wasteful number, since it uses less digits than its factorization.

21846320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450 (or 444 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 21846320 is about 4674.0047068868. The cubic root of 21846320 is about 279.5499573081.

The spelling of 21846320 in words is "twenty-one million, eight hundred forty-six thousand, three hundred twenty".