81758196 has 72 divisors (see below), whose sum is σ = 224983304. Its totient is φ = 24883200.

The previous prime is 81758177. The next prime is 81758203. The reversal of 81758196 is 69185718.

It can be written as a sum of positive squares in 4 ways, for example, as 108900 + 81649296 = 330^2 + 9036^2 .

It is a super-2 number, since 2×81758196² = 13368805226348832, which contains 22 as substring.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 44496 + ... + 46296.

Almost surely, 2^81758196 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 81758196, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112491652).

81758196 is an abundant number, since it is smaller than the sum of its proper divisors (143225108).

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

81758196 is a wasteful number, since it uses less digits than its factorization.

81758196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1921 (or 1916 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 81758196 is about 9042.0238884887. The cubic root of 81758196 is about 434.0206903286.

The spelling of 81758196 in words is "eighty-one million, seven hundred fifty-eight thousand, one hundred ninety-six".