81599349770 has 16 divisors (see below), whose sum is σ = 148393046088. Its totient is φ = 32303247360.

The previous prime is 81599349739. The next prime is 81599349773. The reversal of 81599349770 is 7794399518.

It can be written as a sum of positive squares in 4 ways, for example, as 76633187929 + 4966161841 = 276827^2 + 70471^2 .

It is not an unprimeable number, because it can be changed into a prime (81599349773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42060551 + ... + 42062490.

Almost surely, 2^81599349770 is an apocalyptic number.

81599349770 is a deficient number, since it is larger than the sum of its proper divisors (66793696318).

81599349770 is a wasteful number, since it uses less digits than its factorization.

81599349770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84123145.

The product of its (nonzero) digits is 17146080, while the sum is 62.

The spelling of 81599349770 in words is "eighty-one billion, five hundred ninety-nine million, three hundred forty-nine thousand, seven hundred seventy".