81443842 has 8 divisors (see below), whose sum is σ = 128595600. Its totient is φ = 38578644.

The previous prime is 81443827. The next prime is 81443867. The reversal of 81443842 is 24834418.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 81443798 and 81443807.

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, 1071592 + ... + 1071667.

It is an arithmetic number, because the mean of its divisors is an integer number (16074450).

Almost surely, 2^81443842 is an apocalyptic number.

81443842 is a deficient number, since it is larger than the sum of its proper divisors (47151758).

81443842 is a wasteful number, since it uses less digits than its factorization.

81443842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143280.

The product of its digits is 24576, while the sum is 34.

The square root of 81443842 is about 9024.6242027023. The cubic root of 81443842 is about 433.4637171100.

The spelling of 81443842 in words is "eighty-one million, four hundred forty-three thousand, eight hundred forty-two".