81618126 has 16 divisors (see below), whose sum is σ = 167218128. Its totient is φ = 26542400.

The previous prime is 81618107. The next prime is 81618137. The reversal of 81618126 is 62181618.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165645 + ... + 166136.

It is an arithmetic number, because the mean of its divisors is an integer number (10451133).

Almost surely, 2^81618126 is an apocalyptic number.

81618126 is an abundant number, since it is smaller than the sum of its proper divisors (85600002).

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

81618126 is a wasteful number, since it uses less digits than its factorization.

81618126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331827.

The product of its digits is 4608, while the sum is 33.

The square root of 81618126 is about 9034.2750677628. The cubic root of 81618126 is about 433.7726906107.

The spelling of 81618126 in words is "eighty-one million, six hundred eighteen thousand, one hundred twenty-six".