81079197117 has 8 divisors (see below), whose sum is σ = 108107254560. Its totient is φ = 54051968880.

The previous prime is 81079197083. The next prime is 81079197119. The reversal of 81079197117 is 71179197018.

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

It is not a de Polignac number, because 81079197117 - 2²⁶ = 81012088253 is a prime.

It is a super-2 number, since 2×81079197117² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81079197117.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81079197119) 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, 76267 + ... + 409847.

It is an arithmetic number, because the mean of its divisors is an integer number (13513406820).

Almost surely, 2^81079197117 is an apocalyptic number.

It is an amenable number.

81079197117 is a deficient number, since it is larger than the sum of its proper divisors (27028057443).

81079197117 is a wasteful number, since it uses less digits than its factorization.

81079197117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414603.

The product of its (nonzero) digits is 222264, while the sum is 51.

Subtracting from 81079197117 its reverse (71179197018), we obtain a palindrome (9900000099).

The spelling of 81079197117 in words is "eighty-one billion, seventy-nine million, one hundred ninety-seven thousand, one hundred seventeen".