81005330 has 24 divisors (see below), whose sum is σ = 169616268. Its totient is φ = 27773088.

The previous prime is 81005329. The next prime is 81005363. The reversal of 81005330 is 3350018.

It can be written as a sum of positive squares in 2 ways, for example, as 65141041 + 15864289 = 8071^2 + 3983^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82169 + ... + 83148.

Almost surely, 2^81005330 is an apocalyptic number.

81005330 is an abundant number, since it is smaller than the sum of its proper divisors (88610938).

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

81005330 is a wasteful number, since it uses less digits than its factorization.

81005330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165338 (or 165331 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 81005330 is about 9000.2961062401. The cubic root of 81005330 is about 432.6843612424.

Adding to 81005330 its reverse (3350018), we get a palindrome (84355348).

The spelling of 81005330 in words is "eighty-one million, five thousand, three hundred thirty".