85666564651 has 4 divisors (see below), whose sum is σ = 86025002400. Its totient is φ = 85308126904.

The previous prime is 85666564637. The next prime is 85666564657. The reversal of 85666564651 is 15646566658.

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

It is a cyclic number.

It is not a de Polignac number, because 85666564651 - 2⁵ = 85666564619 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85666564657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179218516 + ... + 179218993.

It is an arithmetic number, because the mean of its divisors is an integer number (21506250600).

Almost surely, 2^85666564651 is an apocalyptic number.

85666564651 is a deficient number, since it is larger than the sum of its proper divisors (358437749).

85666564651 is a wasteful number, since it uses less digits than its factorization.

85666564651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358437748.

The product of its digits is 31104000, while the sum is 58.

The spelling of 85666564651 in words is "eighty-five billion, six hundred sixty-six million, five hundred sixty-four thousand, six hundred fifty-one".