66428773 has 2 divisors, whose sum is σ = 66428774. Its totient is φ = 66428772.

The previous prime is 66428771. The next prime is 66428777. The reversal of 66428773 is 37782466.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56806369 + 9622404 = 7537^2 + 3102^2 .

It is a cyclic number.

It is not a de Polignac number, because 66428773 - 2¹ = 66428771 is a prime.

Together with 66428771, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66428771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33214386 + 33214387.

It is an arithmetic number, because the mean of its divisors is an integer number (33214387).

Almost surely, 2^66428773 is an apocalyptic number.

It is an amenable number.

66428773 is a deficient number, since it is larger than the sum of its proper divisors (1).

66428773 is an equidigital number, since it uses as much as digits as its factorization.

66428773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 338688, while the sum is 43.

The square root of 66428773 is about 8150.3848375399. The cubic root of 66428773 is about 404.9972524327.

The spelling of 66428773 in words is "sixty-six million, four hundred twenty-eight thousand, seven hundred seventy-three".