261697 has 2 divisors, whose sum is σ = 261698. Its totient is φ = 261696.

The previous prime is 261673. The next prime is 261707. The reversal of 261697 is 796162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 261121 + 576 = 511^2 + 24^2 .

It is a cyclic number.

It is not a de Polignac number, because 261697 - 2¹⁵ = 228929 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130848 + 130849.

It is an arithmetic number, because the mean of its divisors is an integer number (130849).

2²⁶¹⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

261697 is a deficient number, since it is larger than the sum of its proper divisors (1).

261697 is an equidigital number, since it uses as much as digits as its factorization.

261697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 31.

The square root of 261697 is about 511.5632903170. The cubic root of 261697 is about 63.9636023510.

The spelling of 261697 in words is "two hundred sixty-one thousand, six hundred ninety-seven".