66855686 has 4 divisors (see below), whose sum is σ = 100283532. Its totient is φ = 33427842.

The previous prime is 66855683. The next prime is 66855689. The reversal of 66855686 is 68655866.

66855686 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (66855683) and next prime (66855689).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66855683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16713920 + ... + 16713923.

It is an arithmetic number, because the mean of its divisors is an integer number (25070883).

Almost surely, 2^66855686 is an apocalyptic number.

66855686 is a deficient number, since it is larger than the sum of its proper divisors (33427846).

66855686 is a wasteful number, since it uses less digits than its factorization.

66855686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33427845.

The product of its digits is 2073600, while the sum is 50.

The square root of 66855686 is about 8176.5326392059. The cubic root of 66855686 is about 405.8629893518.

The spelling of 66855686 in words is "sixty-six million, eight hundred fifty-five thousand, six hundred eighty-six".