21283744 has 12 divisors (see below), whose sum is σ = 41902434. Its totient is φ = 10641856.

The previous prime is 21283739. The next prime is 21283751. The reversal of 21283744 is 44738212.

It can be written as a sum of positive squares in only one way, i.e., 12873744 + 8410000 = 3588^2 + 2900^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332527 + ... + 332590.

Almost surely, 2^21283744 is an apocalyptic number.

It is an amenable number.

21283744 is a deficient number, since it is larger than the sum of its proper divisors (20618690).

21283744 is an equidigital number, since it uses as much as digits as its factorization.

21283744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665127 (or 665119 counting only the distinct ones).

The product of its digits is 10752, while the sum is 31.

The square root of 21283744 is about 4613.4308274862. The cubic root of 21283744 is about 277.1294472455.

The spelling of 21283744 in words is "twenty-one million, two hundred eighty-three thousand, seven hundred forty-four".