855949561 has 2 divisors, whose sum is σ = 855949562. Its totient is φ = 855949560.

The previous prime is 855949513. The next prime is 855949573. The reversal of 855949561 is 165949558.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 653058025 + 202891536 = 25555^2 + 14244^2 .

It is a cyclic number.

It is not a de Polignac number, because 855949561 - 2⁷ = 855949433 is a prime.

It is a super-3 number, since 3×855949561³ (a number of 28 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 855949499 and 855949508.

It is not a weakly prime, because it can be changed into another prime (855949511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427974780 + 427974781.

It is an arithmetic number, because the mean of its divisors is an integer number (427974781).

Almost surely, 2^855949561 is an apocalyptic number.

It is an amenable number.

855949561 is a deficient number, since it is larger than the sum of its proper divisors (1).

855949561 is an equidigital number, since it uses as much as digits as its factorization.

855949561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944000, while the sum is 52.

The square root of 855949561 is about 29256.6156791930. The cubic root of 855949561 is about 949.4732300312.

The spelling of 855949561 in words is "eight hundred fifty-five million, nine hundred forty-nine thousand, five hundred sixty-one".