261306259 has 4 divisors (see below), whose sum is σ = 275059240. Its totient is φ = 247553280.

The previous prime is 261306257. The next prime is 261306281. The reversal of 261306259 is 952603162.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 261306259 - 2¹ = 261306257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261306251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6876462 + ... + 6876499.

It is an arithmetic number, because the mean of its divisors is an integer number (68764810).

Almost surely, 2^261306259 is an apocalyptic number.

261306259 is a deficient number, since it is larger than the sum of its proper divisors (13752981).

261306259 is a wasteful number, since it uses less digits than its factorization.

261306259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13752980.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 261306259 is about 16164.9701206034. The cubic root of 261306259 is about 639.3175171018.

The spelling of 261306259 in words is "two hundred sixty-one million, three hundred six thousand, two hundred fifty-nine".