849220861 has 2 divisors, whose sum is σ = 849220862. Its totient is φ = 849220860.

The previous prime is 849220837. The next prime is 849220901. The reversal of 849220861 is 168022948.

It is an a-pointer prime, because the next prime (849220901) can be obtained adding 849220861 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 778744836 + 70476025 = 27906^2 + 8395^2 .

It is a cyclic number.

It is not a de Polignac number, because 849220861 - 2²³ = 840832253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (849220831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 424610430 + 424610431.

It is an arithmetic number, because the mean of its divisors is an integer number (424610431).

Almost surely, 2^849220861 is an apocalyptic number.

It is an amenable number.

849220861 is a deficient number, since it is larger than the sum of its proper divisors (1).

849220861 is an equidigital number, since it uses as much as digits as its factorization.

849220861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 849220861 is about 29141.3942871648. The cubic root of 849220861 is about 946.9787159113.

The spelling of 849220861 in words is "eight hundred forty-nine million, two hundred twenty thousand, eight hundred sixty-one".