21332423 has 16 divisors (see below), whose sum is σ = 25159680. Its totient is φ = 17707200.

The previous prime is 21332419. The next prime is 21332471. The reversal of 21332423 is 32423312.

It is not a de Polignac number, because 21332423 - 2² = 21332419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21332395 and 21332404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21352423) 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 15 ways as a sum of consecutive naturals, for example, 68438 + ... + 68748.

It is an arithmetic number, because the mean of its divisors is an integer number (1572480).

Almost surely, 2^21332423 is an apocalyptic number.

21332423 is a deficient number, since it is larger than the sum of its proper divisors (3827257).

21332423 is a wasteful number, since it uses less digits than its factorization.

21332423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598.

The product of its digits is 864, while the sum is 20.

The square root of 21332423 is about 4618.7036059916. The cubic root of 21332423 is about 277.3405647474.

Adding to 21332423 its reverse (32423312), we get a palindrome (53755735).

The spelling of 21332423 in words is "twenty-one million, three hundred thirty-two thousand, four hundred twenty-three".