180001891085 has 4 divisors (see below), whose sum is σ = 216002269308. Its totient is φ = 144001512864.

The previous prime is 180001891081. The next prime is 180001891093. The reversal of 180001891085 is 580198100081.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 580198100081 = 10627 ⋅54596603.

It can be written as a sum of positive squares in 2 ways, for example, as 28378097764 + 151623793321 = 168458^2 + 389389^2 .

It is a cyclic number.

It is not a de Polignac number, because 180001891085 - 2² = 180001891081 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (180001891081) 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, 18000189104 + ... + 18000189113.

It is an arithmetic number, because the mean of its divisors is an integer number (54000567327).

Almost surely, 2^180001891085 is an apocalyptic number.

It is an amenable number.

180001891085 is a deficient number, since it is larger than the sum of its proper divisors (36000378223).

180001891085 is an equidigital number, since it uses as much as digits as its factorization.

180001891085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36000378222.

The product of its (nonzero) digits is 23040, while the sum is 41.

The spelling of 180001891085 in words is "one hundred eighty billion, one million, eight hundred ninety-one thousand, eighty-five".