21668303 has 12 divisors (see below), whose sum is σ = 23061168. Its totient is φ = 20355840.

The previous prime is 21668299. The next prime is 21668327. The reversal of 21668303 is 30386612.

It is not a de Polignac number, because 21668303 - 2² = 21668299 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21668203) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 69518 + ... + 69828.

It is an arithmetic number, because the mean of its divisors is an integer number (1921764).

Almost surely, 2^21668303 is an apocalyptic number.

21668303 is a deficient number, since it is larger than the sum of its proper divisors (1392865).

21668303 is a wasteful number, since it uses less digits than its factorization.

21668303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542 (or 523 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 21668303 is about 4654.9224483336. The cubic root of 21668303 is about 278.7885715492.

The spelling of 21668303 in words is "twenty-one million, six hundred sixty-eight thousand, three hundred three".