161925220 has 48 divisors (see below), whose sum is σ = 361569600. Its totient is φ = 60739200.

The previous prime is 161925217. The next prime is 161925223. The reversal of 161925220 is 22529161.

It is an interprime number because it is at equal distance from previous prime (161925217) and next prime (161925223).

It is not an unprimeable number, because it can be changed into a prime (161925223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36271 + ... + 40489.

It is an arithmetic number, because the mean of its divisors is an integer number (7532700).

Almost surely, 2^161925220 is an apocalyptic number.

161925220 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 161925220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (180784800).

161925220 is an abundant number, since it is smaller than the sum of its proper divisors (199644380).

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

161925220 is a wasteful number, since it uses less digits than its factorization.

161925220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4348 (or 4346 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 161925220 is about 12724.9840864341. The cubic root of 161925220 is about 545.0522857561.

It can be divided in two parts, 16192 and 5220, that added together give a palindrome (21412).

The spelling of 161925220 in words is "one hundred sixty-one million, nine hundred twenty-five thousand, two hundred twenty".