21348773 has 2 divisors, whose sum is σ = 21348774. Its totient is φ = 21348772.

The previous prime is 21348749. The next prime is 21348781. The reversal of 21348773 is 37784312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15108769 + 6240004 = 3887^2 + 2498^2 .

It is a cyclic number.

It is not a de Polignac number, because 21348773 - 2⁸ = 21348517 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 (21348713) 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, 10674386 + 10674387.

It is an arithmetic number, because the mean of its divisors is an integer number (10674387).

Almost surely, 2^21348773 is an apocalyptic number.

It is an amenable number.

21348773 is a deficient number, since it is larger than the sum of its proper divisors (1).

21348773 is an equidigital number, since it uses as much as digits as its factorization.

21348773 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 35.

The square root of 21348773 is about 4620.4732441602. The cubic root of 21348773 is about 277.4114015240.

The spelling of 21348773 in words is "twenty-one million, three hundred forty-eight thousand, seven hundred seventy-three".