21068586 has 96 divisors (see below), whose sum is σ = 59125248. Its totient is φ = 5462640.

The previous prime is 21068569. The next prime is 21068609. The reversal of 21068586 is 68586012.

It is a happy number.

21068586 is a `hidden beast` number, since 2 + 10 + 68 + 586 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21068586.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 37141 + ... + 37703.

It is an arithmetic number, because the mean of its divisors is an integer number (615888).

Almost surely, 2^21068586 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21068586, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29562624).

21068586 is an abundant number, since it is smaller than the sum of its proper divisors (38056662).

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

21068586 is a wasteful number, since it uses less digits than its factorization.

21068586 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598 (or 586 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 21068586 is about 4590.0529408712. The cubic root of 21068586 is about 276.1924461224.

The spelling of 21068586 in words is "twenty-one million, sixty-eight thousand, five hundred eighty-six".