81641712188139 has 8 divisors (see below), whose sum is σ = 108858109169040. Its totient is φ = 54426561666336.

The previous prime is 81641712188087. The next prime is 81641712188143. The reversal of 81641712188139 is 93188121714618.

It is a happy number.

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

It is not a de Polignac number, because 81641712188139 - 2¹¹ = 81641712186091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81641712184139) 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, 311461932 + ... + 311723945.

It is an arithmetic number, because the mean of its divisors is an integer number (13607263646130).

Almost surely, 2^{81641712188139} is an apocalyptic number.

81641712188139 is a deficient number, since it is larger than the sum of its proper divisors (27216396980901).

81641712188139 is a wasteful number, since it uses less digits than its factorization.

81641712188139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623229549.

The product of its digits is 4644864, while the sum is 60.

The spelling of 81641712188139 in words is "eighty-one trillion, six hundred forty-one billion, seven hundred twelve million, one hundred eighty-eight thousand, one hundred thirty-nine".