261359617 has 2 divisors, whose sum is σ = 261359618. Its totient is φ = 261359616.

The previous prime is 261359599. The next prime is 261359639. The reversal of 261359617 is 716953162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213043216 + 48316401 = 14596^2 + 6951^2 .

It is a cyclic number.

It is not a de Polignac number, because 261359617 - 2⁷ = 261359489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261359617.

It is not a weakly prime, because it can be changed into another prime (261359647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130679808 + 130679809.

It is an arithmetic number, because the mean of its divisors is an integer number (130679809).

Almost surely, 2^261359617 is an apocalyptic number.

It is an amenable number.

261359617 is a deficient number, since it is larger than the sum of its proper divisors (1).

261359617 is an equidigital number, since it uses as much as digits as its factorization.

261359617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 40.

The square root of 261359617 is about 16166.6204569786. The cubic root of 261359617 is about 639.3610297506.

The spelling of 261359617 in words is "two hundred sixty-one million, three hundred fifty-nine thousand, six hundred seventeen".