91090201 has 2 divisors, whose sum is σ = 91090202. Its totient is φ = 91090200.

The previous prime is 91090171. The next prime is 91090243. The reversal of 91090201 is 10209019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87403801 + 3686400 = 9349^2 + 1920^2 .

It is a cyclic number.

It is not a de Polignac number, because 91090201 - 2¹³ = 91082009 is a prime.

It is not a weakly prime, because it can be changed into another prime (91090271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45545100 + 45545101.

It is an arithmetic number, because the mean of its divisors is an integer number (45545101).

Almost surely, 2^91090201 is an apocalyptic number.

It is an amenable number.

91090201 is a deficient number, since it is larger than the sum of its proper divisors (1).

91090201 is an equidigital number, since it uses as much as digits as its factorization.

91090201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 91090201 is about 9544.1186602012. The cubic root of 91090201 is about 449.9427104022.

The spelling of 91090201 in words is "ninety-one million, ninety thousand, two hundred one".