91121201 has 2 divisors, whose sum is σ = 91121202. Its totient is φ = 91121200.

The previous prime is 91121197. The next prime is 91121209. The reversal of 91121201 is 10212119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78304801 + 12816400 = 8849^2 + 3580^2 .

It is an emirp because it is prime and its reverse (10212119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91121201 - 2² = 91121197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91121201.

It is not a weakly prime, because it can be changed into another prime (91121209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45560600 + 45560601.

It is an arithmetic number, because the mean of its divisors is an integer number (45560601).

Almost surely, 2^91121201 is an apocalyptic number.

It is an amenable number.

91121201 is a deficient number, since it is larger than the sum of its proper divisors (1).

91121201 is an equidigital number, since it uses as much as digits as its factorization.

91121201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 91121201 is about 9545.7425588584. The cubic root of 91121201 is about 449.9937464152.

The spelling of 91121201 in words is "ninety-one million, one hundred twenty-one thousand, two hundred one".