9111212081 has 2 divisors, whose sum is σ = 9111212082. Its totient is φ = 9111212080.

The previous prime is 9111212069. The next prime is 9111212137. The reversal of 9111212081 is 1802121119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7341747856 + 1769464225 = 85684^2 + 42065^2 .

It is a cyclic number.

It is not a de Polignac number, because 9111212081 - 2⁶ = 9111212017 is a prime.

It is a super-2 number, since 2×9111212081² (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 9111212081.

It is not a weakly prime, because it can be changed into another prime (9111212021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4555606040 + 4555606041.

It is an arithmetic number, because the mean of its divisors is an integer number (4555606041).

Almost surely, 2^9111212081 is an apocalyptic number.

It is an amenable number.

9111212081 is a deficient number, since it is larger than the sum of its proper divisors (1).

9111212081 is an equidigital number, since it uses as much as digits as its factorization.

9111212081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 26.

The square root of 9111212081 is about 95452.6693235972. The cubic root of 9111212081 is about 2088.6165673545.

The spelling of 9111212081 in words is "nine billion, one hundred eleven million, two hundred twelve thousand, eighty-one".