81158133 has 8 divisors (see below), whose sum is σ = 123669568. Its totient is φ = 46376064.

The previous prime is 81158113. The next prime is 81158141. The reversal of 81158133 is 33185118.

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

It is not a de Polignac number, because 81158133 - 2⁹ = 81157621 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81158133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81158113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1932316 + ... + 1932357.

It is an arithmetic number, because the mean of its divisors is an integer number (15458696).

Almost surely, 2^81158133 is an apocalyptic number.

It is an amenable number.

81158133 is a deficient number, since it is larger than the sum of its proper divisors (42511435).

81158133 is a wasteful number, since it uses less digits than its factorization.

81158133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3864683.

The product of its digits is 2880, while the sum is 30.

The square root of 81158133 is about 9008.7808831162. The cubic root of 81158133 is about 432.9562525695.

The spelling of 81158133 in words is "eighty-one million, one hundred fifty-eight thousand, one hundred thirty-three".