261917 has 2 divisors, whose sum is σ = 261918. Its totient is φ = 261916.

The previous prime is 261887. The next prime is 261959. The reversal of 261917 is 719162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198916 + 63001 = 446^2 + 251^2 .

It is a cyclic number.

It is not a de Polignac number, because 261917 - 2¹⁰ = 260893 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261917.

It is not a weakly prime, because it can be changed into another prime (261977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130958 + 130959.

It is an arithmetic number, because the mean of its divisors is an integer number (130959).

2²⁶¹⁹¹⁷ is an apocalyptic number.

It is an amenable number.

261917 is a deficient number, since it is larger than the sum of its proper divisors (1).

261917 is an equidigital number, since it uses as much as digits as its factorization.

261917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 26.

The square root of 261917 is about 511.7782723016. The cubic root of 261917 is about 63.9815213579.

The spelling of 261917 in words is "two hundred sixty-one thousand, nine hundred seventeen".