261305313 has 4 divisors (see below), whose sum is σ = 348407088. Its totient is φ = 174203540.

The previous prime is 261305269. The next prime is 261305321. The reversal of 261305313 is 313503162.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261305313 - 2¹³ = 261297121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261305353) 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, 43550883 + ... + 43550888.

It is an arithmetic number, because the mean of its divisors is an integer number (87101772).

Almost surely, 2^261305313 is an apocalyptic number.

It is an amenable number.

261305313 is a deficient number, since it is larger than the sum of its proper divisors (87101775).

261305313 is an equidigital number, since it uses as much as digits as its factorization.

261305313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87101774.

The product of its (nonzero) digits is 1620, while the sum is 24.

The square root of 261305313 is about 16164.9408597743. The cubic root of 261305313 is about 639.3167455996.

Adding to 261305313 its reverse (313503162), we get a palindrome (574808475).

The spelling of 261305313 in words is "two hundred sixty-one million, three hundred five thousand, three hundred thirteen".