261304305 has 16 divisors (see below), whose sum is σ = 422148480. Its totient is φ = 138008448.

The previous prime is 261304279. The next prime is 261304339. The reversal of 261304305 is 503403162.

It is a happy number.

It is not a de Polignac number, because 261304305 - 2⁵ = 261304273 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83020 + ... + 86109.

It is an arithmetic number, because the mean of its divisors is an integer number (26384280).

Almost surely, 2^261304305 is an apocalyptic number.

It is an amenable number.

261304305 is a deficient number, since it is larger than the sum of its proper divisors (160844175).

261304305 is a wasteful number, since it uses less digits than its factorization.

261304305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169240.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 261304305 is about 16164.9096811581. The cubic root of 261304305 is about 639.3159235317.

Adding to 261304305 its reverse (503403162), we get a palindrome (764707467).

The spelling of 261304305 in words is "two hundred sixty-one million, three hundred four thousand, three hundred five".