555721213 has 2 divisors, whose sum is σ = 555721214. Its totient is φ = 555721212.

The previous prime is 555721169. The next prime is 555721219. The reversal of 555721213 is 312127555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398920729 + 156800484 = 19973^2 + 12522^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-555721213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (555721219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277860606 + 277860607.

It is an arithmetic number, because the mean of its divisors is an integer number (277860607).

Almost surely, 2^555721213 is an apocalyptic number.

It is an amenable number.

555721213 is a deficient number, since it is larger than the sum of its proper divisors (1).

555721213 is an equidigital number, since it uses as much as digits as its factorization.

555721213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10500, while the sum is 31.

The square root of 555721213 is about 23573.7399026968. The cubic root of 555721213 is about 822.1523926013.

Adding to 555721213 its reverse (312127555), we get a palindrome (867848768).

The spelling of 555721213 in words is "five hundred fifty-five million, seven hundred twenty-one thousand, two hundred thirteen".