81889594715 has 4 divisors (see below), whose sum is σ = 98267513664. Its totient is φ = 65511675768.

The previous prime is 81889594681. The next prime is 81889594723. The reversal of 81889594715 is 51749598818.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81889594715 - 2²² = 81885400411 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8188959467 + ... + 8188959476.

It is an arithmetic number, because the mean of its divisors is an integer number (24566878416).

Almost surely, 2^81889594715 is an apocalyptic number.

81889594715 is a deficient number, since it is larger than the sum of its proper divisors (16377918949).

81889594715 is a wasteful number, since it uses less digits than its factorization.

81889594715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16377918948.

The product of its digits is 29030400, while the sum is 65.

The spelling of 81889594715 in words is "eighty-one billion, eight hundred eighty-nine million, five hundred ninety-four thousand, seven hundred fifteen".