21304066 has 16 divisors (see below), whose sum is σ = 37299456. Its totient is φ = 8935776.

The previous prime is 21304061. The next prime is 21304069. The reversal of 21304066 is 66040312.

It is not an unprimeable number, because it can be changed into a prime (21304061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15531 + ... + 16846.

It is an arithmetic number, because the mean of its divisors is an integer number (2331216).

Almost surely, 2^21304066 is an apocalyptic number.

21304066 is a deficient number, since it is larger than the sum of its proper divisors (15995390).

21304066 is a wasteful number, since it uses less digits than its factorization.

21304066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32433.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 21304066 is about 4615.6327843536. The cubic root of 21304066 is about 277.2176214742.

Adding to 21304066 its reverse (66040312), we get a palindrome (87344378).

The spelling of 21304066 in words is "twenty-one million, three hundred four thousand, sixty-six".