81101805871 has 8 divisors (see below), whose sum is σ = 85875950304. Its totient is φ = 76328044800.

The previous prime is 81101805847. The next prime is 81101805893. The reversal of 81101805871 is 17850810118.

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 81101805871 - 2³⁵ = 46742067503 is a prime.

It is a super-4 number, since 4×81101805871⁴ (a number of 45 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81105805871) 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, 418686 + ... + 580948.

It is an arithmetic number, because the mean of its divisors is an integer number (10734493788).

Almost surely, 2^81101805871 is an apocalyptic number.

81101805871 is a deficient number, since it is larger than the sum of its proper divisors (4774144433).

81101805871 is a wasteful number, since it uses less digits than its factorization.

81101805871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191681.

The product of its (nonzero) digits is 17920, while the sum is 40.

The spelling of 81101805871 in words is "eighty-one billion, one hundred one million, eight hundred five thousand, eight hundred seventy-one".