66858577585866 has 192 divisors, whose sum is σ = 161318572272000. Its totient is φ = 19841443430400.

The previous prime is 66858577585847. The next prime is 66858577585897.

66858577585866 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10240244490 + ... + 10240251018.

It is an arithmetic number, because the mean of its divisors is an integer number (840200897250).

Almost surely, 2^{66858577585866} is an apocalyptic number.

66858577585866 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66858577585866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80659286136000).

66858577585866 is an abundant number, since it is smaller than the sum of its proper divisors (94459994686134).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66858577585866 is a wasteful number, since it uses less digits than its factorization.

66858577585866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10165 (or 10162 counting only the distinct ones).

The product of its digits is 162570240000, while the sum is 90.

The spelling of 66858577585866 in words is "sixty-six trillion, eight hundred fifty-eight billion, five hundred seventy-seven million, five hundred eighty-five thousand, eight hundred sixty-six".