21328023 has 8 divisors (see below), whose sum is σ = 28645488. Its totient is φ = 14114624.

The previous prime is 21328019. The next prime is 21328057. The reversal of 21328023 is 32082312.

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 21328023 - 2² = 21328019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21328003) 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, 25536 + ... + 26357.

It is an arithmetic number, because the mean of its divisors is an integer number (3580686).

Almost surely, 2^21328023 is an apocalyptic number.

21328023 is a deficient number, since it is larger than the sum of its proper divisors (7317465).

21328023 is a wasteful number, since it uses less digits than its factorization.

21328023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52033.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21328023 is about 4618.2272572926. The cubic root of 21328023 is about 277.3214954588.

The spelling of 21328023 in words is "twenty-one million, three hundred twenty-eight thousand, twenty-three".