21075773 has 2 divisors, whose sum is σ = 21075774. Its totient is φ = 21075772.

The previous prime is 21075749. The next prime is 21075781. The reversal of 21075773 is 37757012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13823524 + 7252249 = 3718^2 + 2693^2 .

It is a cyclic number.

It is not a de Polignac number, because 21075773 - 2¹⁶ = 21010237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21075713) 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 as a sum of consecutive naturals, namely, 10537886 + 10537887.

It is an arithmetic number, because the mean of its divisors is an integer number (10537887).

Almost surely, 2^21075773 is an apocalyptic number.

It is an amenable number.

21075773 is a deficient number, since it is larger than the sum of its proper divisors (1).

21075773 is an equidigital number, since it uses as much as digits as its factorization.

21075773 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10290, while the sum is 32.

The square root of 21075773 is about 4590.8357626907. The cubic root of 21075773 is about 276.2238478413.

The spelling of 21075773 in words is "twenty-one million, seventy-five thousand, seven hundred seventy-three".