1091911001 has 2 divisors, whose sum is σ = 1091911002. Its totient is φ = 1091911000.

The previous prime is 1091910971. The next prime is 1091911013. The reversal of 1091911001 is 1001191901.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 945501001 + 146410000 = 30749^2 + 12100^2 .

It is an emirp because it is prime and its reverse (1001191901) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1091911001 is a prime.

It is not a weakly prime, because it can be changed into another prime (1091911801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545955500 + 545955501.

It is an arithmetic number, because the mean of its divisors is an integer number (545955501).

Almost surely, 2^1091911001 is an apocalyptic number.

It is an amenable number.

1091911001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091911001 is an equidigital number, since it uses as much as digits as its factorization.

1091911001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81, while the sum is 23.

The square root of 1091911001 is about 33044.0766401484. The cubic root of 1091911001 is about 1029.7435503813.

The spelling of 1091911001 in words is "one billion, ninety-one million, nine hundred eleven thousand, one".