21270773 has 2 divisors, whose sum is σ = 21270774. Its totient is φ = 21270772.

The previous prime is 21270763. The next prime is 21270779. The reversal of 21270773 is 37707212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20593444 + 677329 = 4538^2 + 823^2 .

It is a cyclic number.

It is not a de Polignac number, because 21270773 - 2¹⁶ = 21205237 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21270779) 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 as a sum of consecutive naturals, namely, 10635386 + 10635387.

It is an arithmetic number, because the mean of its divisors is an integer number (10635387).

Almost surely, 2^21270773 is an apocalyptic number.

It is an amenable number.

21270773 is a deficient number, since it is larger than the sum of its proper divisors (1).

21270773 is an equidigital number, since it uses as much as digits as its factorization.

21270773 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4116, while the sum is 29.

The square root of 21270773 is about 4612.0248264726. The cubic root of 21270773 is about 277.0731385977.

Adding to 21270773 its reverse (37707212), we get a palindrome (58977985).

The spelling of 21270773 in words is "twenty-one million, two hundred seventy thousand, seven hundred seventy-three".