91479221 has 2 divisors, whose sum is σ = 91479222. Its totient is φ = 91479220.

The previous prime is 91479217. The next prime is 91479247. The reversal of 91479221 is 12297419.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90459121 + 1020100 = 9511^2 + 1010^2 .

It is an emirp because it is prime and its reverse (12297419) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91479221 - 2² = 91479217 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is equal to p_5297831 and since 91479221 and 5297831 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91479121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45739610 + 45739611.

It is an arithmetic number, because the mean of its divisors is an integer number (45739611).

Almost surely, 2^91479221 is an apocalyptic number.

It is an amenable number.

91479221 is a deficient number, since it is larger than the sum of its proper divisors (1).

91479221 is an equidigital number, since it uses as much as digits as its factorization.

91479221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 91479221 is about 9564.4770374548. The cubic root of 91479221 is about 450.5823259470.

The spelling of 91479221 in words is "ninety-one million, four hundred seventy-nine thousand, two hundred twenty-one".