81085083173 has 2 divisors, whose sum is σ = 81085083174. Its totient is φ = 81085083172.

The previous prime is 81085083139. The next prime is 81085083227. The reversal of 81085083173 is 37138058018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80720196769 + 364886404 = 284113^2 + 19102^2 .

It is a cyclic number.

It is not a de Polignac number, because 81085083173 - 2²⁴ = 81068305957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81085083113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40542541586 + 40542541587.

It is an arithmetic number, because the mean of its divisors is an integer number (40542541587).

Almost surely, 2^81085083173 is an apocalyptic number.

It is an amenable number.

81085083173 is a deficient number, since it is larger than the sum of its proper divisors (1).

81085083173 is an equidigital number, since it uses as much as digits as its factorization.

81085083173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 81085083173 in words is "eighty-one billion, eighty-five million, eighty-three thousand, one hundred seventy-three".