21389333 has 12 divisors (see below), whose sum is σ = 25964640. Its totient is φ = 17535672.

The previous prime is 21389323. The next prime is 21389351. The reversal of 21389333 is 33398312.

It is not a de Polignac number, because 21389333 - 2⁴ = 21389317 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21389333.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21389323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8363 + ... + 10616.

It is an arithmetic number, because the mean of its divisors is an integer number (2163720).

Almost surely, 2^21389333 is an apocalyptic number.

21389333 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21389333 is a deficient number, since it is larger than the sum of its proper divisors (4575307).

21389333 is a wasteful number, since it uses less digits than its factorization.

21389333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19016 (or 19009 counting only the distinct ones).

The product of its digits is 11664, while the sum is 32.

The square root of 21389333 is about 4624.8603222151. The cubic root of 21389333 is about 277.5869727115.

The spelling of 21389333 in words is "twenty-one million, three hundred eighty-nine thousand, three hundred thirty-three".