21075443 has 8 divisors (see below), whose sum is σ = 22020096. Its totient is φ = 20147400.

The previous prime is 21075437. The next prime is 21075451. The reversal of 21075443 is 34457012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21075443 - 2¹⁰ = 21074419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21075403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1523 + ... + 6668.

It is an arithmetic number, because the mean of its divisors is an integer number (2752512).

Almost surely, 2^21075443 is an apocalyptic number.

21075443 is a deficient number, since it is larger than the sum of its proper divisors (944653).

21075443 is an equidigital number, since it uses as much as digits as its factorization.

21075443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8305.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 21075443 is about 4590.7998213819. The cubic root of 21075443 is about 276.2224061489. Note that the first 3 decimals are identical.

The spelling of 21075443 in words is "twenty-one million, seventy-five thousand, four hundred forty-three".