66218706 has 24 divisors (see below), whose sum is σ = 151914204. Its totient is φ = 20774400.

The previous prime is 66218701. The next prime is 66218741. The reversal of 66218706 is 60781266.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 63345681 + 2873025 = 7959^2 + 1695^2 .

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66218701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107895 + ... + 108506.

Almost surely, 2^66218706 is an apocalyptic number.

66218706 is an abundant number, since it is smaller than the sum of its proper divisors (85695498).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66218706 is a wasteful number, since it uses less digits than its factorization.

66218706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216426 (or 216423 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 66218706 is about 8137.4876958432. The cubic root of 66218706 is about 404.5698954770.

The spelling of 66218706 in words is "sixty-six million, two hundred eighteen thousand, seven hundred six".