81044387 has 8 divisors (see below), whose sum is σ = 84740640. Its totient is φ = 77509080.

The previous prime is 81044371. The next prime is 81044399. The reversal of 81044387 is 78344018.

It is a happy number.

It is not a de Polignac number, because 81044387 - 2⁴ = 81044371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81044317) 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 7 ways as a sum of consecutive naturals, for example, 8837 + ... + 15497.

It is an arithmetic number, because the mean of its divisors is an integer number (10592580).

Almost surely, 2^81044387 is an apocalyptic number.

81044387 is a deficient number, since it is larger than the sum of its proper divisors (3696253).

81044387 is an frugal number, since it uses more digits than its factorization.

81044387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6730 (or 6684 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 81044387 is about 9002.4656067102. The cubic root of 81044387 is about 432.7538901561.

The spelling of 81044387 in words is "eighty-one million, forty-four thousand, three hundred eighty-seven".