21185223 has 8 divisors (see below), whose sum is σ = 28374528. Its totient is φ = 14059704.

The previous prime is 21185221. The next prime is 21185243. The reversal of 21185223 is 32258112.

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

It is not a de Polignac number, because 21185223 - 2¹ = 21185221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21185193 and 21185202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21185221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15165 + ... + 16502.

It is an arithmetic number, because the mean of its divisors is an integer number (3546816).

Almost surely, 2^21185223 is an apocalyptic number.

21185223 is a deficient number, since it is larger than the sum of its proper divisors (7189305).

21185223 is a wasteful number, since it uses less digits than its factorization.

21185223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31893.

The product of its digits is 960, while the sum is 24.

The square root of 21185223 is about 4602.7408139064. The cubic root of 21185223 is about 276.7011813201.

The spelling of 21185223 in words is "twenty-one million, one hundred eighty-five thousand, two hundred twenty-three".