21075473 has 2 divisors, whose sum is σ = 21075474. Its totient is φ = 21075472.

The previous prime is 21075463. The next prime is 21075487. The reversal of 21075473 is 37457012.

21075473 is nontrivially palindromic in base 8.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20866624 + 208849 = 4568^2 + 457^2 .

It is a cyclic number.

It is not a de Polignac number, because 21075473 - 2⁸ = 21075217 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21075403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10537736 + 10537737.

It is an arithmetic number, because the mean of its divisors is an integer number (10537737).

Almost surely, 2^21075473 is an apocalyptic number.

It is an amenable number.

21075473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21075473 is an equidigital number, since it uses as much as digits as its factorization.

21075473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 21075473 is about 4590.8030887852. The cubic root of 21075473 is about 276.2225372125. Note that the first 3 decimals are identical.

The spelling of 21075473 in words is "twenty-one million, seventy-five thousand, four hundred seventy-three".