161120220 has 96 divisors (see below), whose sum is σ = 481578048. Its totient is φ = 40108032.

The previous prime is 161120207. The next prime is 161120231. The reversal of 161120220 is 22021161.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 161120220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139164 + ... + 140316.

It is an arithmetic number, because the mean of its divisors is an integer number (5016438).

Almost surely, 2^161120220 is an apocalyptic number.

161120220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161120220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (240789024).

161120220 is an abundant number, since it is smaller than the sum of its proper divisors (320457828).

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

161120220 is a wasteful number, since it uses less digits than its factorization.

161120220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1319 (or 1317 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 161120220 is about 12693.3139880805. The cubic root of 161120220 is about 544.1475549490.

Adding to 161120220 its reverse (22021161), we get a palindrome (183141381).

The spelling of 161120220 in words is "one hundred sixty-one million, one hundred twenty thousand, two hundred twenty".