161730 has 32 divisors (see below), whose sum is σ = 432000. Its totient is φ = 43056.

The previous prime is 161729. The next prime is 161731. The reversal of 161730 is 37161.

It is an interprime number because it is at equal distance from previous prime (161729) and next prime (161731).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (161731) 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, 30 + ... + 569.

It is an arithmetic number, because the mean of its divisors is an integer number (13500).

2¹⁶¹⁷³⁰ is an apocalyptic number.

161730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216000).

161730 is an abundant number, since it is smaller than the sum of its proper divisors (270270).

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

161730 is a wasteful number, since it uses less digits than its factorization.

161730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615 (or 609 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 161730 is about 402.1566858825. The cubic root of 161730 is about 54.4833156010.

Subtracting from 161730 its product of nonzero digits (126), we obtain a square (161604 = 402²).

Adding to 161730 its reverse (37161), we get a palindrome (198891).

The spelling of 161730 in words is "one hundred sixty-one thousand, seven hundred thirty".