161260565 has 4 divisors (see below), whose sum is σ = 193512684. Its totient is φ = 129008448.

The previous prime is 161260559. The next prime is 161260591. The reversal of 161260565 is 565062161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 565062161 = 18041 ⋅31321.

It can be written as a sum of positive squares in 2 ways, for example, as 101646724 + 59613841 = 10082^2 + 7721^2 .

It is a cyclic number.

It is not a de Polignac number, because 161260565 - 2⁶ = 161260501 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

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, 16126052 + ... + 16126061.

It is an arithmetic number, because the mean of its divisors is an integer number (48378171).

Almost surely, 2^161260565 is an apocalyptic number.

It is an amenable number.

161260565 is a deficient number, since it is larger than the sum of its proper divisors (32252119).

161260565 is an equidigital number, since it uses as much as digits as its factorization.

161260565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32252118.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 161260565 is about 12698.8410888553. The cubic root of 161260565 is about 544.3055037269.

The spelling of 161260565 in words is "one hundred sixty-one million, two hundred sixty thousand, five hundred sixty-five".