1009190909981 has 2 divisors, whose sum is σ = 1009190909982. Its totient is φ = 1009190909980.

The previous prime is 1009190909971. The next prime is 1009190910173. The reversal of 1009190909981 is 1899090919001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 987022380100 + 22168529881 = 993490^2 + 148891^2 .

It is an emirp because it is prime and its reverse (1899090919001) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1009190909981 is a prime.

It is a super-2 number, since 2×1009190909981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1009190909971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 504595454990 + 504595454991.

It is an arithmetic number, because the mean of its divisors is an integer number (504595454991).

Almost surely, 2^{1009190909981} is an apocalyptic number.

It is an amenable number.

1009190909981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1009190909981 is an equidigital number, since it uses as much as digits as its factorization.

1009190909981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 472392, while the sum is 56.

The spelling of 1009190909981 in words is "one trillion, nine billion, one hundred ninety million, nine hundred nine thousand, nine hundred eighty-one".