261361361 has 4 divisors (see below), whose sum is σ = 262137252. Its totient is φ = 260585472.

The previous prime is 261361297. The next prime is 261361363. The reversal of 261361361 is 163163162.

It is a happy number.

261361361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 163163162 = 2 ⋅81581581.

It can be written as a sum of positive squares in 2 ways, for example, as 31990336 + 229371025 = 5656^2 + 15145^2 .

It is a cyclic number.

It is not a de Polignac number, because 261361361 - 2⁶ = 261361297 is a prime.

It is a super-2 number, since 2×261361361² = 136619522047544642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261361363) 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, 387440 + ... + 388113.

It is an arithmetic number, because the mean of its divisors is an integer number (65534313).

Almost surely, 2^261361361 is an apocalyptic number.

It is an amenable number.

261361361 is a deficient number, since it is larger than the sum of its proper divisors (775891).

261361361 is an equidigital number, since it uses as much as digits as its factorization.

261361361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775890.

The product of its digits is 3888, while the sum is 29.

The square root of 261361361 is about 16166.6743951872. The cubic root of 261361361 is about 639.3624518565.

The spelling of 261361361 in words is "two hundred sixty-one million, three hundred sixty-one thousand, three hundred sixty-one".