9100009981 has 2 divisors, whose sum is σ = 9100009982. Its totient is φ = 9100009980.

The previous prime is 9100009969. The next prime is 9100010033. The reversal of 9100009981 is 1899000019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8743933081 + 356076900 = 93509^2 + 18870^2 .

It is a cyclic number.

It is not a de Polignac number, because 9100009981 - 2⁵ = 9100009949 is a prime.

It is a super-2 number, since 2×9100009981² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 9100009981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9100009381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4550004990 + 4550004991.

It is an arithmetic number, because the mean of its divisors is an integer number (4550004991).

Almost surely, 2^9100009981 is an apocalyptic number.

It is an amenable number.

9100009981 is a deficient number, since it is larger than the sum of its proper divisors (1).

9100009981 is an equidigital number, since it uses as much as digits as its factorization.

9100009981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 37.

The square root of 9100009981 is about 95393.9724563350. The cubic root of 9100009981 is about 2087.7602419572.

The spelling of 9100009981 in words is "nine billion, one hundred million, nine thousand, nine hundred eighty-one".