66889567 has 4 divisors (see below), whose sum is σ = 66906000. Its totient is φ = 66873136.

The previous prime is 66889561. The next prime is 66889621. The reversal of 66889567 is 76598866.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 76598866 = 2 ⋅38299433.

It is a cyclic number.

It is not a de Polignac number, because 66889567 - 2⁷ = 66889439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66889561) 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 3 ways as a sum of consecutive naturals, for example, 2934 + ... + 11932.

It is an arithmetic number, because the mean of its divisors is an integer number (16726500).

Almost surely, 2^66889567 is an apocalyptic number.

66889567 is a deficient number, since it is larger than the sum of its proper divisors (16433).

66889567 is an equidigital number, since it uses as much as digits as its factorization.

66889567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16432.

The product of its digits is 4354560, while the sum is 55.

The square root of 66889567 is about 8178.6042207702. The cubic root of 66889567 is about 405.9315386032.

The spelling of 66889567 in words is "sixty-six million, eight hundred eighty-nine thousand, five hundred sixty-seven".