66694931 has 4 divisors (see below), whose sum is σ = 66723264. Its totient is φ = 66666600.

The previous prime is 66694897. The next prime is 66694951. The reversal of 66694931 is 13949666.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66694931 is a prime.

It is a super-2 number, since 2×66694931² = 8896427642189522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66694951) 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, 10280 + ... + 15461.

It is an arithmetic number, because the mean of its divisors is an integer number (16680816).

Almost surely, 2^66694931 is an apocalyptic number.

66694931 is a deficient number, since it is larger than the sum of its proper divisors (28333).

66694931 is a wasteful number, since it uses less digits than its factorization.

66694931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28332.

The product of its digits is 209952, while the sum is 44.

The square root of 66694931 is about 8166.6964557280. The cubic root of 66694931 is about 405.5374280702.

The spelling of 66694931 in words is "sixty-six million, six hundred ninety-four thousand, nine hundred thirty-one".