21286080 has 168 divisors, whose sum is σ = 77266800. Its totient is φ = 5363712.

The previous prime is 21286073. The next prime is 21286081. The reversal of 21286080 is 8068212.

It is not an unprimeable number, because it can be changed into a prime (21286081) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54526 + ... + 54914.

Almost surely, 2^21286080 is an apocalyptic number.

21286080 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 21286080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38633400).

21286080 is an abundant number, since it is smaller than the sum of its proper divisors (55980720).

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

21286080 is a wasteful number, since it uses less digits than its factorization.

21286080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21286080 is about 4613.6839943802. The cubic root of 21286080 is about 277.1395856671.

The spelling of 21286080 in words is "twenty-one million, two hundred eighty-six thousand, eighty".