81758208 has 96 divisors (see below), whose sum is σ = 249238080. Its totient is φ = 23347200.

The previous prime is 81758203. The next prime is 81758227. The reversal of 81758208 is 80285718.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (81758203) 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, 42058 + ... + 43958.

It is an arithmetic number, because the mean of its divisors is an integer number (2596230).

Almost surely, 2^81758208 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 81758208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124619040).

81758208 is an abundant number, since it is smaller than the sum of its proper divisors (167479872).

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

81758208 is a wasteful number, since it uses less digits than its factorization.

81758208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1933 (or 1913 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 39.

The square root of 81758208 is about 9042.0245520569. The cubic root of 81758208 is about 434.0207115630.

The spelling of 81758208 in words is "eighty-one million, seven hundred fifty-eight thousand, two hundred eight".