81881710443 has 36 divisors (see below), whose sum is σ = 127921157728. Its totient is φ = 50171568480.

The previous prime is 81881710439. The next prime is 81881710483. The reversal of 81881710443 is 34401718818.

81881710443 is a `hidden beast` number, since 8 + 188 + 17 + 10 + 443 = 666.

It is not a de Polignac number, because 81881710443 - 2² = 81881710439 is a prime.

It is a super-2 number, since 2×81881710443² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81881710403) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 50952346 + ... + 50953952.

Almost surely, 2^81881710443 is an apocalyptic number.

81881710443 is a deficient number, since it is larger than the sum of its proper divisors (46039447285).

81881710443 is a wasteful number, since it uses less digits than its factorization.

81881710443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3504 (or 1894 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 45.

The spelling of 81881710443 in words is "eighty-one billion, eight hundred eighty-one million, seven hundred ten thousand, four hundred forty-three".