181800802161 has 32 divisors (see below), whose sum is σ = 311102985600. Its totient is φ = 103700989440.

The previous prime is 181800802147. The next prime is 181800802171. The reversal of 181800802161 is 161208008181.

It is a happy number.

It is not a de Polignac number, because 181800802161 - 2¹³ = 181800793969 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (181800802121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17998596 + ... + 18008693.

It is an arithmetic number, because the mean of its divisors is an integer number (9721968300).

Almost surely, 2^181800802161 is an apocalyptic number.

181800802161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

181800802161 is a deficient number, since it is larger than the sum of its proper divisors (129302183439).

181800802161 is a wasteful number, since it uses less digits than its factorization.

181800802161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36007326 (or 36007320 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 36.

The spelling of 181800802161 in words is "one hundred eighty-one billion, eight hundred million, eight hundred two thousand, one hundred sixty-one".