849781561 has 2 divisors, whose sum is σ = 849781562. Its totient is φ = 849781560.

The previous prime is 849781547. The next prime is 849781571. The reversal of 849781561 is 165187948.

849781561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 848615161 + 1166400 = 29131^2 + 1080^2 .

It is a cyclic number.

It is not a de Polignac number, because 849781561 - 2²³ = 841392953 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (849781571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 424890780 + 424890781.

It is an arithmetic number, because the mean of its divisors is an integer number (424890781).

Almost surely, 2^849781561 is an apocalyptic number.

It is an amenable number.

849781561 is a deficient number, since it is larger than the sum of its proper divisors (1).

849781561 is an equidigital number, since it uses as much as digits as its factorization.

849781561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 49.

The square root of 849781561 is about 29151.0130355705. The cubic root of 849781561 is about 947.1870850078.

The spelling of 849781561 in words is "eight hundred forty-nine million, seven hundred eighty-one thousand, five hundred sixty-one".