81388318 has 16 divisors (see below), whose sum is σ = 133331184. Its totient is φ = 36952960.

The previous prime is 81388313. The next prime is 81388319.

81388318 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81388313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26646 + ... + 29542.

It is an arithmetic number, because the mean of its divisors is an integer number (8333199).

Almost surely, 2^81388318 is an apocalyptic number.

81388318 is a deficient number, since it is larger than the sum of its proper divisors (51942866).

81388318 is a wasteful number, since it uses less digits than its factorization.

81388318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4187.

The product of its digits is 36864, while the sum is 40.

The square root of 81388318 is about 9021.5474282409. The cubic root of 81388318 is about 433.3651906888.

The spelling of 81388318 in words is "eighty-one million, three hundred eighty-eight thousand, three hundred eighteen".