81093190208 has 28 divisors (see below), whose sum is σ = 164844165612. Its totient is φ = 39557652480.

The previous prime is 81093190201. The next prime is 81093190247. The reversal of 81093190208 is 80209139018.

It can be written as a sum of positive squares in 2 ways, for example, as 48819786304 + 32273403904 = 220952^2 + 179648^2 .

It is a super-2 number, since 2×81093190208² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (81093190201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15449585 + ... + 15454832.

It is an arithmetic number, because the mean of its divisors is an integer number (5887291629).

Almost surely, 2^81093190208 is an apocalyptic number.

It is an amenable number.

81093190208 is an abundant number, since it is smaller than the sum of its proper divisors (83750975404).

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

81093190208 is a wasteful number, since it uses less digits than its factorization.

81093190208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30904470 (or 30904460 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 41.

The spelling of 81093190208 in words is "eighty-one billion, ninety-three million, one hundred ninety thousand, two hundred eight".