261064247 has 2 divisors, whose sum is σ = 261064248. Its totient is φ = 261064246.

The previous prime is 261064217. The next prime is 261064249. The reversal of 261064247 is 742460162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261064247 - 2¹⁰ = 261063223 is a prime.

Together with 261064249, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261064249) 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, 130532123 + 130532124.

It is an arithmetic number, because the mean of its divisors is an integer number (130532124).

Almost surely, 2^261064247 is an apocalyptic number.

261064247 is a deficient number, since it is larger than the sum of its proper divisors (1).

261064247 is an equidigital number, since it uses as much as digits as its factorization.

261064247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 261064247 is about 16157.4826937862. The cubic root of 261064247 is about 639.1200855488.

The spelling of 261064247 in words is "two hundred sixty-one million, sixty-four thousand, two hundred forty-seven".