66199686 has 64 divisors (see below), whose sum is σ = 162624000. Its totient is φ = 17908128.

The previous prime is 66199673. The next prime is 66199691. The reversal of 66199686 is 68699166.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38256 + ... + 39948.

It is an arithmetic number, because the mean of its divisors is an integer number (2541000).

Almost surely, 2^66199686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66199686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81312000).

66199686 is an abundant number, since it is smaller than the sum of its proper divisors (96424314).

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

66199686 is a wasteful number, since it uses less digits than its factorization.

66199686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1738 (or 1724 counting only the distinct ones).

The product of its digits is 839808, while the sum is 51.

The square root of 66199686 is about 8136.3189465507. The cubic root of 66199686 is about 404.5311568952.

The spelling of 66199686 in words is "sixty-six million, one hundred ninety-nine thousand, six hundred eighty-six".