66868086805 has 16 divisors (see below), whose sum is σ = 86464499184. Its totient is φ = 49350735360.

The previous prime is 66868086799. The next prime is 66868086811. The reversal of 66868086805 is 50868086866.

It is an interprime number because it is at equal distance from previous prime (66868086799) and next prime (66868086811).

It can be written as a sum of positive squares in 8 ways, for example, as 51523684 + 66816563121 = 7178^2 + 258489^2 .

It is not a de Polignac number, because 66868086805 - 2⁹ = 66868086293 is a prime.

It is a super-2 number, since 2×66868086805² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 187014 + ... + 410743.

It is an arithmetic number, because the mean of its divisors is an integer number (5404031199).

Almost surely, 2^66868086805 is an apocalyptic number.

66868086805 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66868086805 is a deficient number, since it is larger than the sum of its proper divisors (19596412379).

66868086805 is a wasteful number, since it uses less digits than its factorization.

66868086805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599496.

The product of its (nonzero) digits is 26542080, while the sum is 61.

Adding to 66868086805 its sum of digits (61), we get a palindrome (66868086866).

The spelling of 66868086805 in words is "sixty-six billion, eight hundred sixty-eight million, eighty-six thousand, eight hundred five".