81158124 has 48 divisors (see below), whose sum is σ = 202245120. Its totient is φ = 25273920.

The previous prime is 81158113. The next prime is 81158141. The reversal of 81158124 is 42185118.

81158124 = 1603² + 1604² + ... + 1633².

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81158091 and 81158100.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7027 + ... + 14549.

It is an arithmetic number, because the mean of its divisors is an integer number (4213440).

Almost surely, 2^81158124 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81158124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101122560).

81158124 is an abundant number, since it is smaller than the sum of its proper divisors (121086996).

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

81158124 is a wasteful number, since it uses less digits than its factorization.

81158124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7590 (or 7588 counting only the distinct ones).

The product of its digits is 2560, while the sum is 30.

The square root of 81158124 is about 9008.7803836035. The cubic root of 81158124 is about 432.9562365653.

The spelling of 81158124 in words is "eighty-one million, one hundred fifty-eight thousand, one hundred twenty-four".