21283449 has 32 divisors (see below), whose sum is σ = 32081280. Its totient is φ = 12441600.

The previous prime is 21283447. The next prime is 21283463. The reversal of 21283449 is 94438212.

It is not a de Polignac number, because 21283449 - 2¹ = 21283447 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21283447) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 195207 + ... + 195315.

It is an arithmetic number, because the mean of its divisors is an integer number (1002540).

Almost surely, 2^21283449 is an apocalyptic number.

It is an amenable number.

21283449 is a deficient number, since it is larger than the sum of its proper divisors (10797831).

21283449 is a wasteful number, since it uses less digits than its factorization.

21283449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281.

The product of its digits is 13824, while the sum is 33.

The square root of 21283449 is about 4613.3988555077. The cubic root of 21283449 is about 277.1281668698.

The spelling of 21283449 in words is "twenty-one million, two hundred eighty-three thousand, four hundred forty-nine".