161501 has 4 divisors (see below), whose sum is σ = 167100. Its totient is φ = 155904.

The previous prime is 161471. The next prime is 161503. The reversal of 161501 is 105161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 55225 + 106276 = 235^2 + 326^2 .

It is a de Polignac number, because none of the positive numbers 2^k-161501 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2756 + ... + 2813.

It is an arithmetic number, because the mean of its divisors is an integer number (41775).

2¹⁶¹⁵⁰¹ is an apocalyptic number.

It is an amenable number.

161501 is a deficient number, since it is larger than the sum of its proper divisors (5599).

161501 is an equidigital number, since it uses as much as digits as its factorization.

161501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5598.

The product of its (nonzero) digits is 30, while the sum is 14.

The square root of 161501 is about 401.8718701278. The cubic root of 161501 is about 54.4575884165.

Adding to 161501 its reverse (105161), we get a palindrome (266662).

The spelling of 161501 in words is "one hundred sixty-one thousand, five hundred one".