21532423 has 8 divisors (see below), whose sum is σ = 23536656. Its totient is φ = 19536000.

The previous prime is 21532417. The next prime is 21532499. The reversal of 21532423 is 32423512.

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

It is not a de Polignac number, because 21532423 - 2¹³ = 21524231 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21532394 and 21532403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21532403) 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, 4873 + ... + 8173.

It is an arithmetic number, because the mean of its divisors is an integer number (2942082).

Almost surely, 2^21532423 is an apocalyptic number.

21532423 is a deficient number, since it is larger than the sum of its proper divisors (2004233).

21532423 is a wasteful number, since it uses less digits than its factorization.

21532423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3905.

The product of its digits is 1440, while the sum is 22.

The square root of 21532423 is about 4640.3041926150. The cubic root of 21532423 is about 278.2045963824.

Adding to 21532423 its reverse (32423512), we get a palindrome (53955935).

The spelling of 21532423 in words is "twenty-one million, five hundred thirty-two thousand, four hundred twenty-three".