81188118 has 96 divisors (see below), whose sum is σ = 200727072. Its totient is φ = 23500800.

The previous prime is 81188113. The next prime is 81188119.

81188118 is nontrivially palindromic in base 10.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

81188118 is a strobogrammatic number because it is the same when read upside-down.

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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 592546 + ... + 592682.

It is an arithmetic number, because the mean of its divisors is an integer number (2090907).

Almost surely, 2^81188118 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81188118, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100363536).

81188118 is an abundant number, since it is smaller than the sum of its proper divisors (119538954).

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

81188118 is a wasteful number, since it uses less digits than its factorization.

81188118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 267 counting only the distinct ones).

The product of its digits is 4096, while the sum is 36.

The square root of 81188118 is about 9010.4449390693. Note that the first 3 decimals coincide. The cubic root of 81188118 is about 433.0095665721.

The spelling of 81188118 in words is "eighty-one million, one hundred eighty-eight thousand, one hundred eighteen".