161989186 has 16 divisors (see below), whose sum is σ = 251667000. Its totient is φ = 78107008.

The previous prime is 161989169. The next prime is 161989189. The reversal of 161989186 is 681989161.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 161772961 + 216225 = 12719^2 + 465^2 .

It is not an unprimeable number, because it can be changed into a prime (161989189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82140 + ... + 84088.

Almost surely, 2^161989186 is an apocalyptic number.

161989186 is a deficient number, since it is larger than the sum of its proper divisors (89677814).

161989186 is a wasteful number, since it uses less digits than its factorization.

161989186 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3413.

The product of its digits is 186624, while the sum is 49.

The square root of 161989186 is about 12727.4972402276. The cubic root of 161989186 is about 545.1240477389.

The spelling of 161989186 in words is "one hundred sixty-one million, nine hundred eighty-nine thousand, one hundred eighty-six".