261568667 has 2 divisors, whose sum is σ = 261568668. Its totient is φ = 261568666.

The previous prime is 261568663. The next prime is 261568721. The reversal of 261568667 is 766865162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261568667 - 2² = 261568663 is a prime.

It is not a weakly prime, because it can be changed into another prime (261568663) 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, 130784333 + 130784334.

It is an arithmetic number, because the mean of its divisors is an integer number (130784334).

Almost surely, 2^261568667 is an apocalyptic number.

261568667 is a deficient number, since it is larger than the sum of its proper divisors (1).

261568667 is an equidigital number, since it uses as much as digits as its factorization.

261568667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 47.

The square root of 261568667 is about 16173.0846470301. The cubic root of 261568667 is about 639.5314498596.

The spelling of 261568667 in words is "two hundred sixty-one million, five hundred sixty-eight thousand, six hundred sixty-seven".