81888143 has 4 divisors (see below), whose sum is σ = 84529728. Its totient is φ = 79246560.

The previous prime is 81888139. The next prime is 81888151. The reversal of 81888143 is 34188818.

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 81888143 - 2² = 81888139 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81888143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81888943) by changing a digit.

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, 1320746 + ... + 1320807.

It is an arithmetic number, because the mean of its divisors is an integer number (21132432).

Almost surely, 2^81888143 is an apocalyptic number.

81888143 is a deficient number, since it is larger than the sum of its proper divisors (2641585).

81888143 is a wasteful number, since it uses less digits than its factorization.

81888143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2641584.

The product of its digits is 49152, while the sum is 41.

The square root of 81888143 is about 9049.2067608161. The cubic root of 81888143 is about 434.2505136984.

The spelling of 81888143 in words is "eighty-one million, eight hundred eighty-eight thousand, one hundred forty-three".