65666855 has 4 divisors (see below), whose sum is σ = 78800232. Its totient is φ = 52533480.

The previous prime is 65666851. The next prime is 65666857. The reversal of 65666855 is 55866656.

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

It is not a de Polignac number, because 65666855 - 2² = 65666851 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65666851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6566681 + ... + 6566690.

It is an arithmetic number, because the mean of its divisors is an integer number (19700058).

Almost surely, 2^65666855 is an apocalyptic number.

65666855 is a deficient number, since it is larger than the sum of its proper divisors (13133377).

65666855 is a wasteful number, since it uses less digits than its factorization.

65666855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13133376.

The product of its digits is 1296000, while the sum is 47.

The square root of 65666855 is about 8103.5088079177. The cubic root of 65666855 is about 403.4428957339.

The spelling of 65666855 in words is "sixty-five million, six hundred sixty-six thousand, eight hundred fifty-five".