666616856085 has 24 divisors (see below), whose sum is σ = 1155489655320. Its totient is φ = 355522701312.

The previous prime is 666616856083. The next prime is 666616856111. The reversal of 666616856085 is 580658616666.

It can be written as a sum of positive squares in 4 ways, for example, as 13327778916 + 653289077169 = 115446^2 + 808263^2 .

It is not a de Polignac number, because 666616856085 - 2¹ = 666616856083 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666616856083) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3624057 + ... + 3803553.

It is an arithmetic number, because the mean of its divisors is an integer number (48145402305).

Almost surely, 2^666616856085 is an apocalyptic number.

It is an amenable number.

666616856085 is a deficient number, since it is larger than the sum of its proper divisors (488872799235).

666616856085 is a wasteful number, since it uses less digits than its factorization.

666616856085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262037 (or 262034 counting only the distinct ones).

The product of its (nonzero) digits is 74649600, while the sum is 63.

The spelling of 666616856085 in words is "six hundred sixty-six billion, six hundred sixteen million, eight hundred fifty-six thousand, eighty-five".