21323575 has 54 divisors (see below), whose sum is σ = 33629544. Its totient is φ = 13366080.

The previous prime is 21323531. The next prime is 21323591. The reversal of 21323575 is 57532312.

It is not a de Polignac number, because 21323575 - 2¹¹ = 21321527 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 206974 + ... + 207076.

Almost surely, 2^21323575 is an apocalyptic number.

21323575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21323575 is a deficient number, since it is larger than the sum of its proper divisors (12305969).

21323575 is a wasteful number, since it uses less digits than its factorization.

21323575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153 (or 128 counting only the distinct ones).

The product of its digits is 6300, while the sum is 28.

The square root of 21323575 is about 4617.7456621170. The cubic root of 21323575 is about 277.3022154756.

Adding to 21323575 its reverse (57532312), we get a palindrome (78855887).

The spelling of 21323575 in words is "twenty-one million, three hundred twenty-three thousand, five hundred seventy-five".