81366530 has 32 divisors (see below), whose sum is σ = 169686144. Its totient is φ = 27513216.

The previous prime is 81366521. The next prime is 81366533. The reversal of 81366530 is 3566318.

It is not an unprimeable number, because it can be changed into a prime (81366533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2852 + ... + 13071.

It is an arithmetic number, because the mean of its divisors is an integer number (5302692).

Almost surely, 2^81366530 is an apocalyptic number.

81366530 is an abundant number, since it is smaller than the sum of its proper divisors (88319614).

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

81366530 is a wasteful number, since it uses less digits than its factorization.

81366530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16010.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 81366530 is about 9020.3397940432. The cubic root of 81366530 is about 433.3265160006.

The spelling of 81366530 in words is "eighty-one million, three hundred sixty-six thousand, five hundred thirty".