161515 has 4 divisors (see below), whose sum is σ = 193824. Its totient is φ = 129208.

The previous prime is 161507. The next prime is 161521. The reversal of 161515 is 515161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 515161 = 73 ⋅7057.

It is a cyclic number.

It is not a de Polignac number, because 161515 - 2³ = 161507 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161492 and 161501.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16147 + ... + 16156.

It is an arithmetic number, because the mean of its divisors is an integer number (48456).

2¹⁶¹⁵¹⁵ is an apocalyptic number.

161515 is a deficient number, since it is larger than the sum of its proper divisors (32309).

161515 is an equidigital number, since it uses as much as digits as its factorization.

161515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32308.

The product of its digits is 150, while the sum is 19.

The square root of 161515 is about 401.8892882374. The cubic root of 161515 is about 54.4591619551.

Adding to 161515 its reverse (515161), we get a palindrome (676676).

It can be divided in two parts, 161 and 515, that added together give a palindrome (676).

The spelling of 161515 in words is "one hundred sixty-one thousand, five hundred fifteen".