81115443 has 12 divisors (see below), whose sum is σ = 117261768. Its totient is φ = 54033120.

The previous prime is 81115439. The next prime is 81115453. The reversal of 81115443 is 34451118.

It is a happy number.

81115443 is a `hidden beast` number, since 8 + 111 + 544 + 3 = 666.

It is not a de Polignac number, because 81115443 - 2² = 81115439 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81115403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11271 + ... + 17007.

It is an arithmetic number, because the mean of its divisors is an integer number (9771814).

Almost surely, 2^81115443 is an apocalyptic number.

81115443 is a deficient number, since it is larger than the sum of its proper divisors (36146325).

81115443 is a wasteful number, since it uses less digits than its factorization.

81115443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7314 (or 7311 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 81115443 is about 9006.4112164613. The cubic root of 81115443 is about 432.8803261305.

The spelling of 81115443 in words is "eighty-one million, one hundred fifteen thousand, four hundred forty-three".