21009068 has 12 divisors (see below), whose sum is σ = 36820560. Its totient is φ = 10488912.

The previous prime is 21009067. The next prime is 21009091. The reversal of 21009068 is 86090012.

It is not an unprimeable number, because it can be changed into a prime (21009061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 563 + ... + 6506.

It is an arithmetic number, because the mean of its divisors is an integer number (3068380).

Almost surely, 2^21009068 is an apocalyptic number.

It is an amenable number.

21009068 is a deficient number, since it is larger than the sum of its proper divisors (15811492).

21009068 is a wasteful number, since it uses less digits than its factorization.

21009068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7816 (or 7814 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21009068 is about 4583.5649880851. The cubic root of 21009068 is about 275.9321229148.

The spelling of 21009068 in words is "twenty-one million, nine thousand, sixty-eight".