161855289 has 12 divisors (see below), whose sum is σ = 233901616. Its totient is φ = 107852472.

The previous prime is 161855261. The next prime is 161855297. The reversal of 161855289 is 982558161.

It is a happy number.

161855289 is a `hidden beast` number, since 1 + 6 + 18 + 552 + 89 = 666.

It is not a de Polignac number, because 161855289 - 2⁸ = 161855033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161855189) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32862 + ... + 37464.

Almost surely, 2^161855289 is an apocalyptic number.

It is an amenable number.

161855289 is a deficient number, since it is larger than the sum of its proper divisors (72046327).

161855289 is a wasteful number, since it uses less digits than its factorization.

161855289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8516 (or 8513 counting only the distinct ones).

The product of its digits is 172800, while the sum is 45.

The square root of 161855289 is about 12722.2360063002. The cubic root of 161855289 is about 544.9738101490.

The spelling of 161855289 in words is "one hundred sixty-one million, eight hundred fifty-five thousand, two hundred eighty-nine".