161911236 has 48 divisors (see below), whose sum is σ = 401831360. Its totient is φ = 50595840.

The previous prime is 161911199. The next prime is 161911261. The reversal of 161911236 is 632119161.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18456 + ... + 25776.

Almost surely, 2^161911236 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161911236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (200915680).

161911236 is an abundant number, since it is smaller than the sum of its proper divisors (239920124).

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

161911236 is a wasteful number, since it uses less digits than its factorization.

161911236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7444 (or 7442 counting only the distinct ones).

The product of its digits is 1944, while the sum is 30.

The square root of 161911236 is about 12724.4346043351. The cubic root of 161911236 is about 545.0365949111.

The spelling of 161911236 in words is "one hundred sixty-one million, nine hundred eleven thousand, two hundred thirty-six".