81599335090 has 64 divisors (see below), whose sum is σ = 181682726400. Its totient is φ = 25695014400.

The previous prime is 81599335031. The next prime is 81599335099. The reversal of 81599335090 is 9053399518.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81599335099) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44211 + ... + 406390.

It is an arithmetic number, because the mean of its divisors is an integer number (2838792600).

Almost surely, 2^81599335090 is an apocalyptic number.

81599335090 is an abundant number, since it is smaller than the sum of its proper divisors (100083391310).

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

81599335090 is a wasteful number, since it uses less digits than its factorization.

81599335090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450827.

The product of its (nonzero) digits is 1312200, while the sum is 52.

The spelling of 81599335090 in words is "eighty-one billion, five hundred ninety-nine million, three hundred thirty-five thousand, ninety".