66656918 has 4 divisors (see below), whose sum is σ = 99985380. Its totient is φ = 33328458.

The previous prime is 66656911. The next prime is 66656927. The reversal of 66656918 is 81965666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66656911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16664228 + ... + 16664231.

It is an arithmetic number, because the mean of its divisors is an integer number (24996345).

Almost surely, 2^66656918 is an apocalyptic number.

66656918 is a deficient number, since it is larger than the sum of its proper divisors (33328462).

66656918 is a wasteful number, since it uses less digits than its factorization.

66656918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33328461.

The product of its digits is 466560, while the sum is 47.

The square root of 66656918 is about 8164.3688059764. The cubic root of 66656918 is about 405.4603676215.

The spelling of 66656918 in words is "sixty-six million, six hundred fifty-six thousand, nine hundred eighteen".