123205213 has 2 divisors, whose sum is σ = 123205214. Its totient is φ = 123205212.

The previous prime is 123205211. The next prime is 123205219. The reversal of 123205213 is 312502321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72539289 + 50665924 = 8517^2 + 7118^2 .

It is a cyclic number.

It is not a de Polignac number, because 123205213 - 2¹ = 123205211 is a prime.

Together with 123205211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123205211) 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, 61602606 + 61602607.

It is an arithmetic number, because the mean of its divisors is an integer number (61602607).

Almost surely, 2^123205213 is an apocalyptic number.

It is an amenable number.

123205213 is a deficient number, since it is larger than the sum of its proper divisors (1).

123205213 is an equidigital number, since it uses as much as digits as its factorization.

123205213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 123205213 is about 11099.7843672749. The cubic root of 123205213 is about 497.5954050510.

Adding to 123205213 its reverse (312502321), we get a palindrome (435707534).

The spelling of 123205213 in words is "one hundred twenty-three million, two hundred five thousand, two hundred thirteen".