261327709 has 2 divisors, whose sum is σ = 261327710. Its totient is φ = 261327708.

The previous prime is 261327667. The next prime is 261327713. The reversal of 261327709 is 907723162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164403684 + 96924025 = 12822^2 + 9845^2 .

It is a cyclic number.

It is not a de Polignac number, because 261327709 - 2¹³ = 261319517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261327749) 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 as a sum of consecutive naturals, namely, 130663854 + 130663855.

It is an arithmetic number, because the mean of its divisors is an integer number (130663855).

Almost surely, 2^261327709 is an apocalyptic number.

It is an amenable number.

261327709 is a deficient number, since it is larger than the sum of its proper divisors (1).

261327709 is an equidigital number, since it uses as much as digits as its factorization.

261327709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31752, while the sum is 37.

The square root of 261327709 is about 16165.6335786755. The cubic root of 261327709 is about 639.3350099671.

The spelling of 261327709 in words is "two hundred sixty-one million, three hundred twenty-seven thousand, seven hundred nine".