21443264 has 14 divisors (see below), whose sum is σ = 42551604. Its totient is φ = 10721600.

The previous prime is 21443263. The next prime is 21443281. The reversal of 21443264 is 46234412.

It is not an unprimeable number, because it can be changed into a prime (21443263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 167462 + ... + 167589.

Almost surely, 2^21443264 is an apocalyptic number.

It is an amenable number.

21443264 is a deficient number, since it is larger than the sum of its proper divisors (21108340).

21443264 is an equidigital number, since it uses as much as digits as its factorization.

21443264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335063 (or 335053 counting only the distinct ones).

The product of its digits is 4608, while the sum is 26.

The square root of 21443264 is about 4630.6872060203. The cubic root of 21443264 is about 277.8200792230.

Adding to 21443264 its reverse (46234412), we get a palindrome (67677676).

The spelling of 21443264 in words is "twenty-one million, four hundred forty-three thousand, two hundred sixty-four".