161989236 has 36 divisors (see below), whose sum is σ = 409955364. Its totient is φ = 53932800.

The previous prime is 161989199. The next prime is 161989249. The reversal of 161989236 is 632989161.

It is a happy number.

161989236 is a `hidden beast` number, since 1 + 619 + 8 + 9 + 23 + 6 = 666.

161989236 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 140422500 + 21566736 = 11850^2 + 4644^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 161989191 and 161989200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36076 + ... + 40316.

It is an arithmetic number, because the mean of its divisors is an integer number (11387649).

Almost surely, 2^161989236 is an apocalyptic number.

It is an amenable number.

161989236 is an abundant number, since it is smaller than the sum of its proper divisors (247966128).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161989236 is a wasteful number, since it uses less digits than its factorization.

161989236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5312 (or 5307 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 161989236 is about 12727.4992044785. The cubic root of 161989236 is about 545.1241038254.

The spelling of 161989236 in words is "one hundred sixty-one million, nine hundred eighty-nine thousand, two hundred thirty-six".