21445312 has 28 divisors (see below), whose sum is σ = 48635920. Its totient is φ = 9190656.

The previous prime is 21445247. The next prime is 21445327. The reversal of 21445312 is 21354412.

It is a tau number, because it is divible by the number of its divisors (28).

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, 23487 + ... + 24382.

Almost surely, 2^21445312 is an apocalyptic number.

It is an amenable number.

21445312 is an abundant number, since it is smaller than the sum of its proper divisors (27190608).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21445312 is an equidigital number, since it uses as much as digits as its factorization.

21445312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47888 (or 47878 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 21445312 is about 4630.9083342256. The cubic root of 21445312 is about 277.8289236074.

Adding to 21445312 its reverse (21354412), we get a palindrome (42799724).

The spelling of 21445312 in words is "twenty-one million, four hundred forty-five thousand, three hundred twelve".