161502161 has 4 divisors (see below), whose sum is σ = 161532324. Its totient is φ = 161472000.

The previous prime is 161502127. The next prime is 161502163. The reversal of 161502161 is 161205161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 161205161 = 13 ⋅12400397.

It can be written as a sum of positive squares in 2 ways, for example, as 139972561 + 21529600 = 11831^2 + 4640^2 .

It is a cyclic number.

It is not a de Polignac number, because 161502161 - 2¹⁸ = 161240017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161502163) 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, 4640 + ... + 18561.

It is an arithmetic number, because the mean of its divisors is an integer number (40383081).

Almost surely, 2^161502161 is an apocalyptic number.

It is an amenable number.

161502161 is a deficient number, since it is larger than the sum of its proper divisors (30163).

161502161 is an equidigital number, since it uses as much as digits as its factorization.

161502161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30162.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 161502161 is about 12708.3500502622. The cubic root of 161502161 is about 544.5771891122.

The spelling of 161502161 in words is "one hundred sixty-one million, five hundred two thousand, one hundred sixty-one".