21826560 has 264 divisors, whose sum is σ = 84008880. Its totient is φ = 4816896.

The previous prime is 21826549. The next prime is 21826561. The reversal of 21826560 is 6562812.

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

It is not an unprimeable number, because it can be changed into a prime (21826561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 752626 + ... + 752654.

Almost surely, 2^21826560 is an apocalyptic number.

21826560 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 21826560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42004440).

21826560 is an abundant number, since it is smaller than the sum of its proper divisors (62182320).

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

21826560 is a wasteful number, since it uses less digits than its factorization.

21826560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 21826560 is about 4671.8904096736. The cubic root of 21826560 is about 279.4656475563.

The spelling of 21826560 in words is "twenty-one million, eight hundred twenty-six thousand, five hundred sixty".