81886472729 has 8 divisors (see below), whose sum is σ = 90473034240. Its totient is φ = 73718767936.

The previous prime is 81886472663. The next prime is 81886472741. The reversal of 81886472729 is 92727468818.

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

It is a cyclic number.

It is not a de Polignac number, because 81886472729 - 2²⁸ = 81618037273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81886472029) 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, 104713769 + ... + 104714550.

It is an arithmetic number, because the mean of its divisors is an integer number (11309129280).

Almost surely, 2^81886472729 is an apocalyptic number.

It is an amenable number.

81886472729 is a deficient number, since it is larger than the sum of its proper divisors (8586561511).

81886472729 is a wasteful number, since it uses less digits than its factorization.

81886472729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209428359.

The product of its digits is 21676032, while the sum is 62.

The spelling of 81886472729 in words is "eighty-one billion, eight hundred eighty-six million, four hundred seventy-two thousand, seven hundred twenty-nine".