21823173 has 12 divisors (see below), whose sum is σ = 31993728. Its totient is φ = 14331240.

The previous prime is 21823169. The next prime is 21823187. The reversal of 21823173 is 37132812.

It is not a de Polignac number, because 21823173 - 2² = 21823169 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21823103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17493 + ... + 18698.

It is an arithmetic number, because the mean of its divisors is an integer number (2666144).

Almost surely, 2^21823173 is an apocalyptic number.

It is an amenable number.

21823173 is a deficient number, since it is larger than the sum of its proper divisors (10170555).

21823173 is a wasteful number, since it uses less digits than its factorization.

21823173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36264 (or 36261 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 21823173 is about 4671.5279085113. The cubic root of 21823173 is about 279.4511911767.

Adding to 21823173 its reverse (37132812), we get a palindrome (58955985).

The spelling of 21823173 in words is "twenty-one million, eight hundred twenty-three thousand, one hundred seventy-three".