181641865853 has 4 divisors (see below), whose sum is σ = 207590703840. Its totient is φ = 155693027868.

The previous prime is 181641865841. The next prime is 181641865907. The reversal of 181641865853 is 358568146181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 181641865853 - 2⁸ = 181641865597 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 (181641861853) 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, 12974418983 + ... + 12974418996.

It is an arithmetic number, because the mean of its divisors is an integer number (51897675960).

Almost surely, 2^181641865853 is an apocalyptic number.

It is an amenable number.

181641865853 is a deficient number, since it is larger than the sum of its proper divisors (25948837987).

181641865853 is an equidigital number, since it uses as much as digits as its factorization.

181641865853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25948837986.

The product of its digits is 5529600, while the sum is 56.

The spelling of 181641865853 in words is "one hundred eighty-one billion, six hundred forty-one million, eight hundred sixty-five thousand, eight hundred fifty-three".