21360066 has 128 divisors (see below), whose sum is σ = 58060800. Its totient is φ = 5080320.

The previous prime is 21360013. The next prime is 21360083. The reversal of 21360066 is 66006312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 300811 + ... + 300881.

It is an arithmetic number, because the mean of its divisors is an integer number (453600).

Almost surely, 2^21360066 is an apocalyptic number.

21360066 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21360066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29030400).

21360066 is an abundant number, since it is smaller than the sum of its proper divisors (36700734).

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

21360066 is a wasteful number, since it uses less digits than its factorization.

21360066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 21360066 is about 4621.6951435593. The cubic root of 21360066 is about 277.4603076091.

Adding to 21360066 its reverse (66006312), we get a palindrome (87366378).

The spelling of 21360066 in words is "twenty-one million, three hundred sixty thousand, sixty-six".