63218321 has 2 divisors, whose sum is σ = 63218322. Its totient is φ = 63218320.

The previous prime is 63218317. The next prime is 63218327. The reversal of 63218321 is 12381236.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55294096 + 7924225 = 7436^2 + 2815^2 .

It is a cyclic number.

It is not a de Polignac number, because 63218321 - 2² = 63218317 is a prime.

It is a super-2 number, since 2×63218321² = 7993112220118082, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (63218327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31609160 + 31609161.

It is an arithmetic number, because the mean of its divisors is an integer number (31609161).

Almost surely, 2^63218321 is an apocalyptic number.

It is an amenable number.

63218321 is a deficient number, since it is larger than the sum of its proper divisors (1).

63218321 is an equidigital number, since it uses as much as digits as its factorization.

63218321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 26.

The square root of 63218321 is about 7950.9949691847. The cubic root of 63218321 is about 398.3648267127.

Adding to 63218321 its reverse (12381236), we get a palindrome (75599557).

The spelling of 63218321 in words is "sixty-three million, two hundred eighteen thousand, three hundred twenty-one".