261304361 has 4 divisors (see below), whose sum is σ = 261337812. Its totient is φ = 261270912.

The previous prime is 261304339. The next prime is 261304411. The reversal of 261304361 is 163403162.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 10272025 + 251032336 = 3205^2 + 15844^2 .

It is a cyclic number.

It is not a de Polignac number, because 261304361 - 2¹⁰ = 261303337 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261304361.

It is not an unprimeable number, because it can be changed into a prime (261304061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1925 + ... + 22941.

It is an arithmetic number, because the mean of its divisors is an integer number (65334453).

Almost surely, 2^261304361 is an apocalyptic number.

It is an amenable number.

261304361 is a deficient number, since it is larger than the sum of its proper divisors (33451).

261304361 is a wasteful number, since it uses less digits than its factorization.

261304361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33450.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 261304361 is about 16164.9114133051. The cubic root of 261304361 is about 639.3159692022.

The spelling of 261304361 in words is "two hundred sixty-one million, three hundred four thousand, three hundred sixty-one".