161220 has 24 divisors (see below), whose sum is σ = 451584. Its totient is φ = 42976.

The previous prime is 161201. The next prime is 161221. The reversal of 161220 is 22161.

161220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 161196 and 161205.

It is not an unprimeable number, because it can be changed into a prime (161221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1284 + ... + 1403.

It is an arithmetic number, because the mean of its divisors is an integer number (18816).

2¹⁶¹²²⁰ is an apocalyptic number.

161220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161220 is an abundant number, since it is smaller than the sum of its proper divisors (290364).

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

161220 is a wasteful number, since it uses less digits than its factorization.

161220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2699 (or 2697 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 161220 is about 401.5221039993. The cubic root of 161220 is about 54.4259859990.

Adding to 161220 its reverse (22161), we get a palindrome (183381).

The spelling of 161220 in words is "one hundred sixty-one thousand, two hundred twenty".