81106189164 has 576 divisors, whose sum is σ = 286656240640. Its totient is φ = 19296921600.

The previous prime is 81106189141. The next prime is 81106189187. The reversal of 81106189164 is 46198160118.

It is a happy number.

81106189164 is a `hidden beast` number, since 8 + 1 + 10 + 618 + 9 + 16 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (81106189141) and next prime (81106189187).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 286594167 + ... + 286594449.

Almost surely, 2^81106189164 is an apocalyptic number.

81106189164 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81106189164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143328120320).

81106189164 is an abundant number, since it is smaller than the sum of its proper divisors (205550051476).

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

81106189164 is a wasteful number, since it uses less digits than its factorization.

81106189164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 560 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The spelling of 81106189164 in words is "eighty-one billion, one hundred six million, one hundred eighty-nine thousand, one hundred sixty-four".