21773369 has 2 divisors, whose sum is σ = 21773370. Its totient is φ = 21773368.

The previous prime is 21773363. The next prime is 21773371. The reversal of 21773369 is 96337712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21114025 + 659344 = 4595^2 + 812^2 .

It is a cyclic number.

It is not a de Polignac number, because 21773369 - 2²⁰ = 20724793 is a prime.

It is a super-2 number, since 2×21773369² = 948159195220322, which contains 22 as substring.

Together with 21773371, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21773363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10886684 + 10886685.

It is an arithmetic number, because the mean of its divisors is an integer number (10886685).

Almost surely, 2^21773369 is an apocalyptic number.

It is an amenable number.

21773369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21773369 is an equidigital number, since it uses as much as digits as its factorization.

21773369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47628, while the sum is 38.

The square root of 21773369 is about 4666.1942737096. The cubic root of 21773369 is about 279.2384450266.

The spelling of 21773369 in words is "twenty-one million, seven hundred seventy-three thousand, three hundred sixty-nine".