81158244 has 24 divisors (see below), whose sum is σ = 189557760. Its totient is φ = 27025824.

The previous prime is 81158219. The next prime is 81158263. The reversal of 81158244 is 44285118.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11997 + ... + 17499.

It is an arithmetic number, because the mean of its divisors is an integer number (7898240).

Almost surely, 2^81158244 is an apocalyptic number.

It is an amenable number.

81158244 is an abundant number, since it is smaller than the sum of its proper divisors (108399516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81158244 is a wasteful number, since it uses less digits than its factorization.

81158244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6739 (or 6737 counting only the distinct ones).

The product of its digits is 10240, while the sum is 33.

The square root of 81158244 is about 9008.7870437701. The cubic root of 81158244 is about 432.9564499542.

The spelling of 81158244 in words is "eighty-one million, one hundred fifty-eight thousand, two hundred forty-four".