161956 has 12 divisors (see below), whose sum is σ = 298480. Its totient is φ = 76680.

The previous prime is 161947. The next prime is 161957. The reversal of 161956 is 659161.

It is not an unprimeable number, because it can be changed into a prime (161957) by changing a digit.

161956 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 990 + ... + 1141.

2¹⁶¹⁹⁵⁶ is an apocalyptic number.

It is an amenable number.

161956 is a deficient number, since it is larger than the sum of its proper divisors (136524).

161956 is a wasteful number, since it uses less digits than its factorization.

161956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2154 (or 2152 counting only the distinct ones).

The product of its digits is 1620, while the sum is 28.

The square root of 161956 is about 402.4375727986. The cubic root of 161956 is about 54.5086819488.

The spelling of 161956 in words is "one hundred sixty-one thousand, nine hundred fifty-six".