81188101 has 8 divisors (see below), whose sum is σ = 86073344. Its totient is φ = 76444560.

The previous prime is 81188089. The next prime is 81188111. The reversal of 81188101 is 10188118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81188101 - 2⁷ = 81187973 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81188101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81188111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34245 + ... + 36538.

It is an arithmetic number, because the mean of its divisors is an integer number (10759168).

Almost surely, 2^81188101 is an apocalyptic number.

It is an amenable number.

81188101 is a deficient number, since it is larger than the sum of its proper divisors (4885243).

81188101 is a wasteful number, since it uses less digits than its factorization.

81188101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70851.

The product of its (nonzero) digits is 512, while the sum is 28.

The square root of 81188101 is about 9010.4439957196. The cubic root of 81188101 is about 433.0095363494.

The spelling of 81188101 in words is "eighty-one million, one hundred eighty-eight thousand, one hundred one".