66704765 has 4 divisors (see below), whose sum is σ = 80045724. Its totient is φ = 53363808.

The previous prime is 66704749. The next prime is 66704773. The reversal of 66704765 is 56740766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56740766 = 2 ⋅28370383.

It can be written as a sum of positive squares in 2 ways, for example, as 17522596 + 49182169 = 4186^2 + 7013^2 .

It is a cyclic number.

It is not a de Polignac number, because 66704765 - 2⁴ = 66704749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 6670472 + ... + 6670481.

It is an arithmetic number, because the mean of its divisors is an integer number (20011431).

Almost surely, 2^66704765 is an apocalyptic number.

It is an amenable number.

66704765 is a deficient number, since it is larger than the sum of its proper divisors (13340959).

66704765 is a wasteful number, since it uses less digits than its factorization.

66704765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13340958.

The product of its (nonzero) digits is 211680, while the sum is 41.

The square root of 66704765 is about 8167.2985129723. The cubic root of 66704765 is about 405.5573589156.

The spelling of 66704765 in words is "sixty-six million, seven hundred four thousand, seven hundred sixty-five".