21328383 has 8 divisors (see below), whose sum is σ = 29674368. Its totient is φ = 13600664.

The previous prime is 21328381. The next prime is 21328399. The reversal of 21328383 is 38382312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21328383 - 2¹ = 21328381 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21328383.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21328381) 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, 154485 + ... + 154622.

It is an arithmetic number, because the mean of its divisors is an integer number (3709296).

Almost surely, 2^21328383 is an apocalyptic number.

21328383 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21328383 is a deficient number, since it is larger than the sum of its proper divisors (8345985).

21328383 is a wasteful number, since it uses less digits than its factorization.

21328383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309133.

The product of its digits is 6912, while the sum is 30.

The square root of 21328383 is about 4618.2662331226. The cubic root of 21328383 is about 277.3230557718.

The spelling of 21328383 in words is "twenty-one million, three hundred twenty-eight thousand, three hundred eighty-three".