161905836 has 36 divisors (see below), whose sum is σ = 386823192. Its totient is φ = 52706304.

The previous prime is 161905817. The next prime is 161905867. The reversal of 161905836 is 638509161.

It is a junction number, because it is equal to n+sod(n) for n = 161905794 and 161905803.

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, 18540 + ... + 25836.

Almost surely, 2^161905836 is an apocalyptic number.

It is an amenable number.

161905836 is an abundant number, since it is smaller than the sum of its proper divisors (224917356).

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

161905836 is a wasteful number, since it uses less digits than its factorization.

161905836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7390 (or 7345 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 161905836 is about 12724.2224123913. Note that the first 3 decimals coincide. The cubic root of 161905836 is about 545.0305355615.

The spelling of 161905836 in words is "one hundred sixty-one million, nine hundred five thousand, eight hundred thirty-six".