123215321 has 2 divisors, whose sum is σ = 123215322. Its totient is φ = 123215320.

The previous prime is 123215227. The next prime is 123215329. The reversal of 123215321 is 123512321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72250000 + 50965321 = 8500^2 + 7139^2 .

It is an emirp because it is prime and its reverse (123512321) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123215321 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 123215293 and 123215302.

It is not a weakly prime, because it can be changed into another prime (123215329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61607660 + 61607661.

It is an arithmetic number, because the mean of its divisors is an integer number (61607661).

Almost surely, 2^123215321 is an apocalyptic number.

It is an amenable number.

123215321 is a deficient number, since it is larger than the sum of its proper divisors (1).

123215321 is an equidigital number, since it uses as much as digits as its factorization.

123215321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 20.

The square root of 123215321 is about 11100.2396820970. The cubic root of 123215321 is about 497.6090125835.

Adding to 123215321 its reverse (123512321), we get a palindrome (246727642).

The spelling of 123215321 in words is "one hundred twenty-three million, two hundred fifteen thousand, three hundred twenty-one".