261316417 has 2 divisors, whose sum is σ = 261316418. Its totient is φ = 261316416.

The previous prime is 261316399. The next prime is 261316439. The reversal of 261316417 is 714613162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 231983361 + 29333056 = 15231^2 + 5416^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261316417 is a prime.

It is not a weakly prime, because it can be changed into another prime (261316217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130658208 + 130658209.

It is an arithmetic number, because the mean of its divisors is an integer number (130658209).

Almost surely, 2^261316417 is an apocalyptic number.

It is an amenable number.

261316417 is a deficient number, since it is larger than the sum of its proper divisors (1).

261316417 is an equidigital number, since it uses as much as digits as its factorization.

261316417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 261316417 is about 16165.2843154706. The cubic root of 261316417 is about 639.3258012549.

Adding to 261316417 its reverse (714613162), we get a palindrome (975929579).

The spelling of 261316417 in words is "two hundred sixty-one million, three hundred sixteen thousand, four hundred seventeen".