91224409 has 2 divisors, whose sum is σ = 91224410. Its totient is φ = 91224408.

The previous prime is 91224403. The next prime is 91224433. The reversal of 91224409 is 90442219.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69806025 + 21418384 = 8355^2 + 4628^2 .

It is a cyclic number.

It is not a de Polignac number, because 91224409 - 2⁷ = 91224281 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91224403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45612204 + 45612205.

It is an arithmetic number, because the mean of its divisors is an integer number (45612205).

Almost surely, 2^91224409 is an apocalyptic number.

It is an amenable number.

91224409 is a deficient number, since it is larger than the sum of its proper divisors (1).

91224409 is an equidigital number, since it uses as much as digits as its factorization.

91224409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 91224409 is about 9551.1469991829. The cubic root of 91224409 is about 450.1635767460.

It can be divided in two parts, 9122 and 4409, that added together give a palindrome (13531).

The spelling of 91224409 in words is "ninety-one million, two hundred twenty-four thousand, four hundred nine".