9181213 has 2 divisors, whose sum is σ = 9181214. Its totient is φ = 9181212.

The previous prime is 9181201. The next prime is 9181219. The reversal of 9181213 is 3121819.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6365529 + 2815684 = 2523^2 + 1678^2 .

It is a cyclic number.

It is not a de Polignac number, because 9181213 - 2⁵ = 9181181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9181219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4590606 + 4590607.

It is an arithmetic number, because the mean of its divisors is an integer number (4590607).

Almost surely, 2^9181213 is an apocalyptic number.

It is an amenable number.

9181213 is a deficient number, since it is larger than the sum of its proper divisors (1).

9181213 is an equidigital number, since it uses as much as digits as its factorization.

9181213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 25.

The square root of 9181213 is about 3030.0516497248. The cubic root of 9181213 is about 209.3951834111.

The spelling of 9181213 in words is "nine million, one hundred eighty-one thousand, two hundred thirteen".