66694423 has 4 divisors (see below), whose sum is σ = 68845888. Its totient is φ = 64542960.

The previous prime is 66694421. The next prime is 66694429. The reversal of 66694423 is 32449666.

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

It is a cyclic number.

It is not a de Polignac number, because 66694423 - 2¹ = 66694421 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 (66694421) 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, 1075686 + ... + 1075747.

It is an arithmetic number, because the mean of its divisors is an integer number (17211472).

Almost surely, 2^66694423 is an apocalyptic number.

66694423 is a deficient number, since it is larger than the sum of its proper divisors (2151465).

66694423 is a wasteful number, since it uses less digits than its factorization.

66694423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2151464.

The product of its digits is 186624, while the sum is 40.

The square root of 66694423 is about 8166.6653537414. The cubic root of 66694423 is about 405.5363984390.

The spelling of 66694423 in words is "sixty-six million, six hundred ninety-four thousand, four hundred twenty-three".