81388588117 has 16 divisors (see below), whose sum is σ = 82666584000. Its totient is φ = 80118271872.

The previous prime is 81388588111. The next prime is 81388588123. The reversal of 81388588117 is 71188588318.

It is an interprime number because it is at equal distance from previous prime (81388588111) and next prime (81388588123).

It is not a de Polignac number, because 81388588117 - 2¹⁵ = 81388555349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81388588111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35493223 + ... + 35495515.

It is an arithmetic number, because the mean of its divisors is an integer number (5166661500).

Almost surely, 2^81388588117 is an apocalyptic number.

It is an amenable number.

81388588117 is a deficient number, since it is larger than the sum of its proper divisors (1277995883).

81388588117 is a wasteful number, since it uses less digits than its factorization.

81388588117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3732.

The product of its digits is 3440640, while the sum is 58.

The spelling of 81388588117 in words is "eighty-one billion, three hundred eighty-eight million, five hundred eighty-eight thousand, one hundred seventeen".