21323445 has 32 divisors (see below), whose sum is σ = 40086144. Its totient is φ = 9542400.

The previous prime is 21323441. The next prime is 21323473. The reversal of 21323445 is 54432312.

It is not a de Polignac number, because 21323445 - 2² = 21323441 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2826 + ... + 7115.

It is an arithmetic number, because the mean of its divisors is an integer number (1252692).

Almost surely, 2^21323445 is an apocalyptic number.

It is an amenable number.

21323445 is a deficient number, since it is larger than the sum of its proper divisors (18762699).

21323445 is a wasteful number, since it uses less digits than its factorization.

21323445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9973.

The product of its digits is 2880, while the sum is 24.

The square root of 21323445 is about 4617.7315859630. The cubic root of 21323445 is about 277.3016519466.

Adding to 21323445 its reverse (54432312), we get a palindrome (75755757).

The spelling of 21323445 in words is "twenty-one million, three hundred twenty-three thousand, four hundred forty-five".