161785187 has 8 divisors (see below), whose sum is σ = 167519232. Its totient is φ = 156083400.

The previous prime is 161785147. The next prime is 161785193. The reversal of 161785187 is 781587161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161785187 - 2⁶ = 161785123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161785147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2378 + ... + 18144.

It is an arithmetic number, because the mean of its divisors is an integer number (20939904).

Almost surely, 2^161785187 is an apocalyptic number.

161785187 is a deficient number, since it is larger than the sum of its proper divisors (5734045).

161785187 is a wasteful number, since it uses less digits than its factorization.

161785187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16129.

The product of its digits is 94080, while the sum is 44.

The square root of 161785187 is about 12719.4806104652. The cubic root of 161785187 is about 544.8951199579.

The spelling of 161785187 in words is "one hundred sixty-one million, seven hundred eighty-five thousand, one hundred eighty-seven".