23218813 has 2 divisors, whose sum is σ = 23218814. Its totient is φ = 23218812.

The previous prime is 23218777. The next prime is 23218829. The reversal of 23218813 is 31881232.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18983449 + 4235364 = 4357^2 + 2058^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23218813 is a prime.

It is a super-2 number, since 2×23218813² = 1078226554257938, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23218843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11609406 + 11609407.

It is an arithmetic number, because the mean of its divisors is an integer number (11609407).

Almost surely, 2^23218813 is an apocalyptic number.

It is an amenable number.

23218813 is a deficient number, since it is larger than the sum of its proper divisors (1).

23218813 is an equidigital number, since it uses as much as digits as its factorization.

23218813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 28.

The square root of 23218813 is about 4818.5903540351. The cubic root of 23218813 is about 285.2857009839.

The spelling of 23218813 in words is "twenty-three million, two hundred eighteen thousand, eight hundred thirteen".