91091091001 has 2 divisors, whose sum is σ = 91091091002. Its totient is φ = 91091091000.

The previous prime is 91091090947. The next prime is 91091091011. The reversal of 91091091001 is 10019019019.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58583361600 + 32507729401 = 242040^2 + 180299^2 .

It is an emirp because it is prime and its reverse (10019019019) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91091091001 - 2⁷ = 91091090873 is a prime.

It is not a weakly prime, because it can be changed into another prime (91091091011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45545545500 + 45545545501.

It is an arithmetic number, because the mean of its divisors is an integer number (45545545501).

Almost surely, 2^91091091001 is an apocalyptic number.

It is an amenable number.

91091091001 is a deficient number, since it is larger than the sum of its proper divisors (1).

91091091001 is an equidigital number, since it uses as much as digits as its factorization.

91091091001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 31.

The spelling of 91091091001 in words is "ninety-one billion, ninety-one million, ninety-one thousand, one".