66764559 has 32 divisors (see below), whose sum is σ = 97182720. Its totient is φ = 40614912.

The previous prime is 66764549. The next prime is 66764563. The reversal of 66764559 is 95546766.

It is not a de Polignac number, because 66764559 - 2⁸ = 66764303 is a prime.

It is a super-3 number, since 3×66764559³ (a number of 24 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66764549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 294004 + ... + 294230.

It is an arithmetic number, because the mean of its divisors is an integer number (3036960).

Almost surely, 2^66764559 is an apocalyptic number.

66764559 is a deficient number, since it is larger than the sum of its proper divisors (30418161).

66764559 is a wasteful number, since it uses less digits than its factorization.

66764559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399.

The product of its digits is 1360800, while the sum is 48.

The square root of 66764559 is about 8170.9582669354. The cubic root of 66764559 is about 405.6785029571.

The spelling of 66764559 in words is "sixty-six million, seven hundred sixty-four thousand, five hundred fifty-nine".