122720321 has 2 divisors, whose sum is σ = 122720322. Its totient is φ = 122720320.

The previous prime is 122720309. The next prime is 122720347. The reversal of 122720321 is 123027221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111598096 + 11122225 = 10564^2 + 3335^2 .

It is an emirp because it is prime and its reverse (123027221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-122720321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 122720293 and 122720302.

It is not a weakly prime, because it can be changed into another prime (122720621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61360160 + 61360161.

It is an arithmetic number, because the mean of its divisors is an integer number (61360161).

Almost surely, 2^122720321 is an apocalyptic number.

It is an amenable number.

122720321 is a deficient number, since it is larger than the sum of its proper divisors (1).

122720321 is an equidigital number, since it uses as much as digits as its factorization.

122720321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 122720321 is about 11077.9204275893. The cubic root of 122720321 is about 496.9417604797.

Adding to 122720321 its reverse (123027221), we get a palindrome (245747542).

The spelling of 122720321 in words is "one hundred twenty-two million, seven hundred twenty thousand, three hundred twenty-one".