21323215 has 8 divisors (see below), whose sum is σ = 25652880. Its totient is φ = 17015232.

The previous prime is 21323209. The next prime is 21323261. The reversal of 21323215 is 51232312.

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 21323215 - 2⁷ = 21323087 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21323192 and 21323201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3169 + ... + 7258.

It is an arithmetic number, because the mean of its divisors is an integer number (3206610).

Almost surely, 2^21323215 is an apocalyptic number.

21323215 is a deficient number, since it is larger than the sum of its proper divisors (4329665).

21323215 is a wasteful number, since it uses less digits than its factorization.

21323215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10841.

The product of its digits is 360, while the sum is 19.

The square root of 21323215 is about 4617.7066818931. The cubic root of 21323215 is about 277.3006549280.

Adding to 21323215 its reverse (51232312), we get a palindrome (72555527).

The spelling of 21323215 in words is "twenty-one million, three hundred twenty-three thousand, two hundred fifteen".