166610005186581 has 48 divisors (see below), whose sum is σ = 276356988311040. Its totient is φ = 95660459580960.

The previous prime is 166610005186561. The next prime is 166610005186607. The reversal of 166610005186581 is 185681500016661.

It is a happy number.

166610005186581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 166610005186581 - 2⁷ = 166610005186453 is a prime.

It is a super-2 number, since 2×166610005186581² (a number of 29 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166610005186561) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 289437256 + ... + 290012318.

It is an arithmetic number, because the mean of its divisors is an integer number (5757437256480).

Almost surely, 2^{166610005186581} is an apocalyptic number.

166610005186581 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166610005186581 is a deficient number, since it is larger than the sum of its proper divisors (109746983124459).

166610005186581 is a wasteful number, since it uses less digits than its factorization.

166610005186581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729126 (or 729123 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 54.

The spelling of 166610005186581 in words is "one hundred sixty-six trillion, six hundred ten billion, five million, one hundred eighty-six thousand, five hundred eighty-one".