201561512173 has 4 divisors (see below), whose sum is σ = 230356013920. Its totient is φ = 172767010428.

The previous prime is 201561512171. The next prime is 201561512239. The reversal of 201561512173 is 371215165102.

201561512173 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a cyclic number.

It is not a de Polignac number, because 201561512173 - 2¹ = 201561512171 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 (201561512171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14397250863 + ... + 14397250876.

It is an arithmetic number, because the mean of its divisors is an integer number (57589003480).

Almost surely, 2^201561512173 is an apocalyptic number.

It is an amenable number.

201561512173 is a deficient number, since it is larger than the sum of its proper divisors (28794501747).

201561512173 is an equidigital number, since it uses as much as digits as its factorization.

201561512173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28794501746.

The product of its (nonzero) digits is 12600, while the sum is 34.

Adding to 201561512173 its reverse (371215165102), we get a palindrome (572776677275).

The spelling of 201561512173 in words is "two hundred one billion, five hundred sixty-one million, five hundred twelve thousand, one hundred seventy-three".