21323144 has 16 divisors (see below), whose sum is σ = 40029900. Its totient is φ = 10648512.

The previous prime is 21323129. The next prime is 21323153. The reversal of 21323144 is 44132312.

It can be written as a sum of positive squares in 2 ways, for example, as 20884900 + 438244 = 4570^2 + 662^2 .

It is an unprimeable number.

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, 11942 + ... + 13610.

Almost surely, 2^21323144 is an apocalyptic number.

It is an amenable number.

21323144 is a deficient number, since it is larger than the sum of its proper divisors (18706756).

21323144 is a wasteful number, since it uses less digits than its factorization.

21323144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3272 (or 3268 counting only the distinct ones).

The product of its digits is 576, while the sum is 20.

The square root of 21323144 is about 4617.6989940879. The cubic root of 21323144 is about 277.3003471513.

Adding to 21323144 its reverse (44132312), we get a palindrome (65455456).

The spelling of 21323144 in words is "twenty-one million, three hundred twenty-three thousand, one hundred forty-four".