187831887161 has 4 divisors (see below), whose sum is σ = 187896459300. Its totient is φ = 187767315024.

The previous prime is 187831887149. The next prime is 187831887169. The reversal of 187831887161 is 161788138781.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 161117946025 + 26713941136 = 401395^2 + 163444^2 .

It is a cyclic number.

It is not a de Polignac number, because 187831887161 - 2⁶ = 187831887097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 187831887161.

It is not an unprimeable number, because it can be changed into a prime (187831887169) 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, 32281706 + ... + 32287523.

It is an arithmetic number, because the mean of its divisors is an integer number (46974114825).

Almost surely, 2^187831887161 is an apocalyptic number.

It is an amenable number.

187831887161 is a deficient number, since it is larger than the sum of its proper divisors (64572139).

187831887161 is an equidigital number, since it uses as much as digits as its factorization.

187831887161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64572138.

The product of its digits is 3612672, while the sum is 59.

The spelling of 187831887161 in words is "one hundred eighty-seven billion, eight hundred thirty-one million, eight hundred eighty-seven thousand, one hundred sixty-one".