161615 has 4 divisors (see below), whose sum is σ = 193944. Its totient is φ = 129288.

The previous prime is 161611. The next prime is 161627. The reversal of 161615 is 516161.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 161615 - 2² = 161611 is a prime.

It is a super-2 number, since 2×161615² = 52238816450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161611) 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, 16157 + ... + 16166.

It is an arithmetic number, because the mean of its divisors is an integer number (48486).

2¹⁶¹⁶¹⁵ is an apocalyptic number.

161615 is a deficient number, since it is larger than the sum of its proper divisors (32329).

161615 is an equidigital number, since it uses as much as digits as its factorization.

161615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32328.

The product of its digits is 180, while the sum is 20.

The square root of 161615 is about 402.0136813592. The cubic root of 161615 is about 54.4703988736.

Adding to 161615 its reverse (516161), we get a palindrome (677776).

It can be divided in two parts, 1 and 61615, that added together give a palindrome (61616).

The spelling of 161615 in words is "one hundred sixty-one thousand, six hundred fifteen".