81871382 has 8 divisors (see below), whose sum is σ = 122862216. Its totient is φ = 40917312.

The previous prime is 81871357. The next prime is 81871397. The reversal of 81871382 is 28317818.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2708 + ... + 13079.

It is an arithmetic number, because the mean of its divisors is an integer number (15357777).

Almost surely, 2^81871382 is an apocalyptic number.

81871382 is a deficient number, since it is larger than the sum of its proper divisors (40990834).

81871382 is a wasteful number, since it uses less digits than its factorization.

81871382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18382.

The product of its digits is 21504, while the sum is 38.

The square root of 81871382 is about 9048.2806101491. The cubic root of 81871382 is about 434.2208839732.

The spelling of 81871382 in words is "eighty-one million, eight hundred seventy-one thousand, three hundred eighty-two".