81042512 has 20 divisors (see below), whose sum is σ = 159984180. Its totient is φ = 39756288.

The previous prime is 81042509. The next prime is 81042517. The reversal of 81042512 is 21524018.

It can be written as a sum of positive squares in 2 ways, for example, as 21196816 + 59845696 = 4604^2 + 7736^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81042517) 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 3 ways as a sum of consecutive naturals, for example, 46937 + ... + 48632.

It is an arithmetic number, because the mean of its divisors is an integer number (7999209).

Almost surely, 2^81042512 is an apocalyptic number.

It is an amenable number.

81042512 is a deficient number, since it is larger than the sum of its proper divisors (78941668).

81042512 is a wasteful number, since it uses less digits than its factorization.

81042512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95630 (or 95624 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 81042512 is about 9002.3614679705. The cubic root of 81042512 is about 432.7505528087.

The spelling of 81042512 in words is "eighty-one million, forty-two thousand, five hundred twelve".