91811201 has 2 divisors, whose sum is σ = 91811202. Its totient is φ = 91811200.

The previous prime is 91811191. The next prime is 91811207. The reversal of 91811201 is 10211819.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58920976 + 32890225 = 7676^2 + 5735^2 .

It is an emirp because it is prime and its reverse (10211819) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91811201 is a prime.

It is not a weakly prime, because it can be changed into another prime (91811207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45905600 + 45905601.

It is an arithmetic number, because the mean of its divisors is an integer number (45905601).

Almost surely, 2^91811201 is an apocalyptic number.

It is an amenable number.

91811201 is a deficient number, since it is larger than the sum of its proper divisors (1).

91811201 is an equidigital number, since it uses as much as digits as its factorization.

91811201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

The square root of 91811201 is about 9581.8161639639. The cubic root of 91811201 is about 451.1267254826.

The spelling of 91811201 in words is "ninety-one million, eight hundred eleven thousand, two hundred one".