81667832871 has 16 divisors (see below), whose sum is σ = 111274267104. Its totient is φ = 53259408384.

The previous prime is 81667832833. The next prime is 81667832879. The reversal of 81667832871 is 17823876618.

It is not a de Polignac number, because 81667832871 - 2¹¹ = 81667830823 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81667832879) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 708486 + ... + 815651.

It is an arithmetic number, because the mean of its divisors is an integer number (6954641694).

Almost surely, 2^81667832871 is an apocalyptic number.

81667832871 is a deficient number, since it is larger than the sum of its proper divisors (29606434233).

81667832871 is a wasteful number, since it uses less digits than its factorization.

81667832871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1524530.

The product of its digits is 5419008, while the sum is 57.

The spelling of 81667832871 in words is "eighty-one billion, six hundred sixty-seven million, eight hundred thirty-two thousand, eight hundred seventy-one".