66481865 has 16 divisors (see below), whose sum is σ = 81139968. Its totient is φ = 52286016.

The previous prime is 66481861. The next prime is 66481871. The reversal of 66481865 is 56818466.

It is a cyclic number.

It is not a de Polignac number, because 66481865 - 2² = 66481861 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (66481861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85619 + ... + 86391.

It is an arithmetic number, because the mean of its divisors is an integer number (5071248).

Almost surely, 2^66481865 is an apocalyptic number.

It is an amenable number.

66481865 is a deficient number, since it is larger than the sum of its proper divisors (14658103).

66481865 is a wasteful number, since it uses less digits than its factorization.

66481865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048.

The product of its digits is 276480, while the sum is 44.

The square root of 66481865 is about 8153.6412111400. The cubic root of 66481865 is about 405.1051192867.

The spelling of 66481865 in words is "sixty-six million, four hundred eighty-one thousand, eight hundred sixty-five".