91140221 has 2 divisors, whose sum is σ = 91140222. Its totient is φ = 91140220.

The previous prime is 91140199. The next prime is 91140251. The reversal of 91140221 is 12204119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59892121 + 31248100 = 7739^2 + 5590^2 .

It is a cyclic number.

It is not a de Polignac number, because 91140221 - 2⁶ = 91140157 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 91140193 and 91140202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91140251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45570110 + 45570111.

It is an arithmetic number, because the mean of its divisors is an integer number (45570111).

Almost surely, 2^91140221 is an apocalyptic number.

It is an amenable number.

91140221 is a deficient number, since it is larger than the sum of its proper divisors (1).

91140221 is an equidigital number, since it uses as much as digits as its factorization.

91140221 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 20.

The square root of 91140221 is about 9546.7387625304. The cubic root of 91140221 is about 450.0250537491.

The spelling of 91140221 in words is "ninety-one million, one hundred forty thousand, two hundred twenty-one".