66694765 has 4 divisors (see below), whose sum is σ = 80033724. Its totient is φ = 53355808.

The previous prime is 66694753. The next prime is 66694781. The reversal of 66694765 is 56749666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52722121 + 13972644 = 7261^2 + 3738^2 .

It is a cyclic number.

It is not a de Polignac number, because 66694765 - 2⁷ = 66694637 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6669472 + ... + 6669481.

It is an arithmetic number, because the mean of its divisors is an integer number (20008431).

Almost surely, 2^66694765 is an apocalyptic number.

It is an amenable number.

66694765 is a deficient number, since it is larger than the sum of its proper divisors (13338959).

66694765 is a wasteful number, since it uses less digits than its factorization.

66694765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13338958.

The product of its digits is 1632960, while the sum is 49.

The square root of 66694765 is about 8166.6862924934. The cubic root of 66694765 is about 405.5370916165.

The spelling of 66694765 in words is "sixty-six million, six hundred ninety-four thousand, seven hundred sixty-five".