21532323 has 4 divisors (see below), whose sum is σ = 28709768. Its totient is φ = 14354880.

The previous prime is 21532309. The next prime is 21532327. The reversal of 21532323 is 32323512.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21532323 - 2⁴ = 21532307 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21532323.

It is not an unprimeable number, because it can be changed into a prime (21532327) 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 3 ways as a sum of consecutive naturals, for example, 3588718 + ... + 3588723.

It is an arithmetic number, because the mean of its divisors is an integer number (7177442).

Almost surely, 2^21532323 is an apocalyptic number.

21532323 is a deficient number, since it is larger than the sum of its proper divisors (7177445).

21532323 is an equidigital number, since it uses as much as digits as its factorization.

21532323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7177444.

The product of its digits is 1080, while the sum is 21.

The square root of 21532323 is about 4640.2934174468. The cubic root of 21532323 is about 278.2041657063.

Adding to 21532323 its reverse (32323512), we get a palindrome (53855835).

The spelling of 21532323 in words is "twenty-one million, five hundred thirty-two thousand, three hundred twenty-three".