21239223 has 8 divisors (see below), whose sum is σ = 29295600. Its totient is φ = 13671168.

The previous prime is 21239203. The next prime is 21239237. The reversal of 21239223 is 32293212.

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

It is not a de Polignac number, because 21239223 - 2⁵ = 21239191 is a prime.

It is a super-3 number, since 3×21239223³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 21239193 and 21239202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21239203) 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, 121978 + ... + 122151.

It is an arithmetic number, because the mean of its divisors is an integer number (3661950).

Almost surely, 2^21239223 is an apocalyptic number.

21239223 is a deficient number, since it is larger than the sum of its proper divisors (8056377).

21239223 is a wasteful number, since it uses less digits than its factorization.

21239223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244161.

The product of its digits is 1296, while the sum is 24.

The square root of 21239223 is about 4608.6031506304. The cubic root of 21239223 is about 276.9360806868.

The spelling of 21239223 in words is "twenty-one million, two hundred thirty-nine thousand, two hundred twenty-three".