81886125666 has 16 divisors (see below), whose sum is σ = 163778256000. Its totient is φ = 27294374448.

The previous prime is 81886125583. The next prime is 81886125689. The reversal of 81886125666 is 66652168818.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62026 + ... + 409413.

It is an arithmetic number, because the mean of its divisors is an integer number (10236141000).

Almost surely, 2^81886125666 is an apocalyptic number.

81886125666 is an abundant number, since it is smaller than the sum of its proper divisors (81892130334).

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

81886125666 is a wasteful number, since it uses less digits than its factorization.

81886125666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500393.

The product of its digits is 6635520, while the sum is 57.

The spelling of 81886125666 in words is "eighty-one billion, eight hundred eighty-six million, one hundred twenty-five thousand, six hundred sixty-six".