21330023 has 8 divisors (see below), whose sum is σ = 25059216. Its totient is φ = 17899200.

The previous prime is 21329999. The next prime is 21330047. The reversal of 21330023 is 32003312.

It is an interprime number because it is at equal distance from previous prime (21329999) and next prime (21330047).

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

It is not a de Polignac number, because 21330023 - 2¹⁶ = 21264487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330073) 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 7 ways as a sum of consecutive naturals, for example, 74438 + ... + 74723.

It is an arithmetic number, because the mean of its divisors is an integer number (3132402).

Almost surely, 2^21330023 is an apocalyptic number.

21330023 is a deficient number, since it is larger than the sum of its proper divisors (3729193).

21330023 is a wasteful number, since it uses less digits than its factorization.

21330023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149185.

The product of its (nonzero) digits is 108, while the sum is 14.

The square root of 21330023 is about 4618.4437855191. The cubic root of 21330023 is about 277.3301636423.

Adding to 21330023 its reverse (32003312), we get a palindrome (53333335).

Subtracting 21330023 from its reverse (32003312), we obtain a square (10673289 = 3267²).

The spelling of 21330023 in words is "twenty-one million, three hundred thirty thousand, twenty-three".