123020121221 has 2 divisors, whose sum is σ = 123020121222. Its totient is φ = 123020121220.

The previous prime is 123020121181. The next prime is 123020121247. The reversal of 123020121221 is 122121020321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119982568225 + 3037552996 = 346385^2 + 55114^2 .

It is an emirp because it is prime and its reverse (122121020321) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123020121221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123020121221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123020121251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61510060610 + 61510060611.

It is an arithmetic number, because the mean of its divisors is an integer number (61510060611).

Almost surely, 2^123020121221 is an apocalyptic number.

It is an amenable number.

123020121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

123020121221 is an equidigital number, since it uses as much as digits as its factorization.

123020121221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 123020121221 its reverse (122121020321), we get a palindrome (245141141542).

The spelling of 123020121221 in words is "one hundred twenty-three billion, twenty million, one hundred twenty-one thousand, two hundred twenty-one".