81502208 has 28 divisors (see below), whose sum is σ = 163010850. Its totient is φ = 40747008.

The previous prime is 81502189. The next prime is 81502247. The reversal of 81502208 is 80220518.

It can be written as a sum of positive squares in only one way, i.e., 72454144 + 9048064 = 8512^2 + 3008^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3218 + ... + 13166.

Almost surely, 2^81502208 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 81502208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81505425).

81502208 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81502208 is an frugal number, since it uses more digits than its factorization.

81502208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9975 (or 9951 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 81502208 is about 9027.8573316153. The cubic root of 81502208 is about 433.5672383484.

The spelling of 81502208 in words is "eighty-one million, five hundred two thousand, two hundred eight".