161685489 has 16 divisors (see below), whose sum is σ = 246643712. Its totient is φ = 92292048.

The previous prime is 161685473. The next prime is 161685551. The reversal of 161685489 is 984586161.

It is not a de Polignac number, because 161685489 - 2⁴ = 161685473 is a prime.

It is a super-2 number, since 2×161685489² = 52284394706338242, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161685889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18702 + ... + 25944.

It is an arithmetic number, because the mean of its divisors is an integer number (15415232).

Almost surely, 2^161685489 is an apocalyptic number.

It is an amenable number.

161685489 is a deficient number, since it is larger than the sum of its proper divisors (84958223).

161685489 is a wasteful number, since it uses less digits than its factorization.

161685489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8316.

The product of its digits is 414720, while the sum is 48.

The square root of 161685489 is about 12715.5608999367. The cubic root of 161685489 is about 544.7831688011.

The spelling of 161685489 in words is "one hundred sixty-one million, six hundred eighty-five thousand, four hundred eighty-nine".