81073808 has 20 divisors (see below), whose sum is σ = 161327100. Its totient is φ = 39441024.

The previous prime is 81073807. The next prime is 81073813. The reversal of 81073808 is 80837018.

It can be written as a sum of positive squares in 2 ways, for example, as 78357904 + 2715904 = 8852^2 + 1648^2 .

It is not an unprimeable number, because it can be changed into a prime (81073801) 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, 67883 + ... + 69066.

It is an arithmetic number, because the mean of its divisors is an integer number (8066355).

Almost surely, 2^81073808 is an apocalyptic number.

It is an amenable number.

81073808 is a deficient number, since it is larger than the sum of its proper divisors (80253292).

81073808 is a wasteful number, since it uses less digits than its factorization.

81073808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136994 (or 136988 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 81073808 is about 9004.0995107784. The cubic root of 81073808 is about 432.8062504009.

The spelling of 81073808 in words is "eighty-one million, seventy-three thousand, eight hundred eight".