81861274271 has 8 divisors (see below), whose sum is σ = 93570729984. Its totient is φ = 70155565560.

The previous prime is 81861274249. The next prime is 81861274291. The reversal of 81861274271 is 17247216818.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81861274271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81861274291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 889775 + ... + 977456.

It is an arithmetic number, because the mean of its divisors is an integer number (11696341248).

Almost surely, 2^81861274271 is an apocalyptic number.

81861274271 is a deficient number, since it is larger than the sum of its proper divisors (11709455713).

81861274271 is a wasteful number, since it uses less digits than its factorization.

81861274271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1873501.

The product of its digits is 301056, while the sum is 47.

The spelling of 81861274271 in words is "eighty-one billion, eight hundred sixty-one million, two hundred seventy-four thousand, two hundred seventy-one".