91211249 has 2 divisors, whose sum is σ = 91211250. Its totient is φ = 91211248.

The previous prime is 91211233. The next prime is 91211297. The reversal of 91211249 is 94211219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54390625 + 36820624 = 7375^2 + 6068^2 .

It is an emirp because it is prime and its reverse (94211219) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91211249 - 2⁴ = 91211233 is a prime.

It is not a weakly prime, because it can be changed into another prime (91211209) 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, 45605624 + 45605625.

It is an arithmetic number, because the mean of its divisors is an integer number (45605625).

Almost surely, 2^91211249 is an apocalyptic number.

It is an amenable number.

91211249 is a deficient number, since it is larger than the sum of its proper divisors (1).

91211249 is an equidigital number, since it uses as much as digits as its factorization.

91211249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 29.

The square root of 91211249 is about 9550.4580518423. The cubic root of 91211249 is about 450.1419288938.

The spelling of 91211249 in words is "ninety-one million, two hundred eleven thousand, two hundred forty-nine".