161887 has 4 divisors (see below), whose sum is σ = 176616. Its totient is φ = 147160.

The previous prime is 161881. The next prime is 161911. The reversal of 161887 is 788161.

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

It is a cyclic number.

It is not a de Polignac number, because 161887 - 2³ = 161879 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7348 + ... + 7369.

It is an arithmetic number, because the mean of its divisors is an integer number (44154).

2¹⁶¹⁸⁸⁷ is an apocalyptic number.

161887 is a deficient number, since it is larger than the sum of its proper divisors (14729).

161887 is a wasteful number, since it uses less digits than its factorization.

161887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14728.

The product of its digits is 2688, while the sum is 31.

The square root of 161887 is about 402.3518360838. The cubic root of 161887 is about 54.5009398598.

The spelling of 161887 in words is "one hundred sixty-one thousand, eight hundred eighty-seven".