161656 has 24 divisors (see below), whose sum is σ = 335160. Its totient is φ = 73040.

The previous prime is 161641. The next prime is 161659. The reversal of 161656 is 656161.

It is a super-2 number, since 2×161656² = 52265324672, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

Its product of digits (1080) is a multiple of the sum of its prime divisors (180).

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 161656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161659) by changing a digit.

161656 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 885 + ... + 1051.

It is an arithmetic number, because the mean of its divisors is an integer number (13965).

2¹⁶¹⁶⁵⁶ 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 161656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167580).

161656 is an abundant number, since it is smaller than the sum of its proper divisors (173504).

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

161656 is a wasteful number, since it uses less digits than its factorization.

161656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 180 counting only the distinct ones).

The product of its digits is 1080, while the sum is 25.

The square root of 161656 is about 402.0646714149. The cubic root of 161656 is about 54.4750046703.

The spelling of 161656 in words is "one hundred sixty-one thousand, six hundred fifty-six".