518763221 has 2 divisors, whose sum is σ = 518763222. Its totient is φ = 518763220.

The previous prime is 518763191. The next prime is 518763233. The reversal of 518763221 is 122367815.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 500014321 + 18748900 = 22361^2 + 4330^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-518763221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518763121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259381610 + 259381611.

It is an arithmetic number, because the mean of its divisors is an integer number (259381611).

Almost surely, 2^518763221 is an apocalyptic number.

It is an amenable number.

518763221 is a deficient number, since it is larger than the sum of its proper divisors (1).

518763221 is an equidigital number, since it uses as much as digits as its factorization.

518763221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 35.

The square root of 518763221 is about 22776.3741846678. The cubic root of 518763221 is about 803.5071136625.

The spelling of 518763221 in words is "five hundred eighteen million, seven hundred sixty-three thousand, two hundred twenty-one".