161017500 has 120 divisors (see below), whose sum is σ = 536728192. Its totient is φ = 36792000.

The previous prime is 161017477. The next prime is 161017513. The reversal of 161017500 is 5710161.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 50967 + ... + 54033.

Almost surely, 2^161017500 is an apocalyptic number.

161017500 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 161017500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268364096).

161017500 is an abundant number, since it is smaller than the sum of its proper divisors (375710692).

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

161017500 is a wasteful number, since it uses less digits than its factorization.

161017500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3101 (or 3084 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 21.

The square root of 161017500 is about 12689.2671183170. The cubic root of 161017500 is about 544.0318924137.

Adding to 161017500 its reverse (5710161), we get a palindrome (166727661).

It can be divided in two parts, 1610 and 17500, that added together give a triangular number (19110 = T₁₉₅).

The spelling of 161017500 in words is "one hundred sixty-one million, seventeen thousand, five hundred".