66766061 has 4 divisors (see below), whose sum is σ = 68025852. Its totient is φ = 65506272.

The previous prime is 66766043. The next prime is 66766087. The reversal of 66766061 is 16066766.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16066766 = 2 ⋅8033383.

It can be written as a sum of positive squares in 2 ways, for example, as 49084036 + 17682025 = 7006^2 + 4205^2 .

It is a cyclic number.

It is not a de Polignac number, because 66766061 - 2⁶ = 66765997 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 (66766001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 629816 + ... + 629921.

It is an arithmetic number, because the mean of its divisors is an integer number (17006463).

Almost surely, 2^66766061 is an apocalyptic number.

It is an amenable number.

66766061 is a deficient number, since it is larger than the sum of its proper divisors (1259791).

66766061 is a wasteful number, since it uses less digits than its factorization.

66766061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1259790.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 66766061 is about 8171.0501773028. The cubic root of 66766061 is about 405.6815451128.

The spelling of 66766061 in words is "sixty-six million, seven hundred sixty-six thousand, sixty-one".