66228769 has 2 divisors, whose sum is σ = 66228770. Its totient is φ = 66228768.

The previous prime is 66228733. The next prime is 66228793. The reversal of 66228769 is 96782266.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62599744 + 3629025 = 7912^2 + 1905^2 .

It is a cyclic number.

It is not a de Polignac number, because 66228769 - 2¹⁹ = 65704481 is a prime.

It is a super-2 number, since 2×66228769² = 8772499686510722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66228709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33114384 + 33114385.

It is an arithmetic number, because the mean of its divisors is an integer number (33114385).

Almost surely, 2^66228769 is an apocalyptic number.

It is an amenable number.

66228769 is a deficient number, since it is larger than the sum of its proper divisors (1).

66228769 is an equidigital number, since it uses as much as digits as its factorization.

66228769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 46.

The square root of 66228769 is about 8138.1059835812. The cubic root of 66228769 is about 404.5903880784.

The spelling of 66228769 in words is "sixty-six million, two hundred twenty-eight thousand, seven hundred sixty-nine".