9875775781 has 2 divisors, whose sum is σ = 9875775782. Its totient is φ = 9875775780.

The previous prime is 9875775769. The next prime is 9875775809. The reversal of 9875775781 is 1875775789.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9854532900 + 21242881 = 99270^2 + 4609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9875775781 is a prime.

It is a super-2 number, since 2×9875775781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9875775761) 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, 4937887890 + 4937887891.

It is an arithmetic number, because the mean of its divisors is an integer number (4937887891).

Almost surely, 2^9875775781 is an apocalyptic number.

It is an amenable number.

9875775781 is a deficient number, since it is larger than the sum of its proper divisors (1).

9875775781 is an equidigital number, since it uses as much as digits as its factorization.

9875775781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34574400, while the sum is 64.

The square root of 9875775781 is about 99376.9378729290. The cubic root of 9875775781 is about 2145.4763935184.

The spelling of 9875775781 in words is "nine billion, eight hundred seventy-five million, seven hundred seventy-five thousand, seven hundred eighty-one".