123355001221 has 2 divisors, whose sum is σ = 123355001222. Its totient is φ = 123355001220.

The previous prime is 123355001219. The next prime is 123355001233. The reversal of 123355001221 is 122100553321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104451776100 + 18903225121 = 323190^2 + 137489^2 .

It is an emirp because it is prime and its reverse (122100553321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123355001221 - 2¹ = 123355001219 is a prime.

It is a super-2 number, since 2×123355001221² (a number of 23 digits) contains 22 as substring.

Together with 123355001219, 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 (123355001281) 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, 61677500610 + 61677500611.

It is an arithmetic number, because the mean of its divisors is an integer number (61677500611).

Almost surely, 2^123355001221 is an apocalyptic number.

It is an amenable number.

123355001221 is a deficient number, since it is larger than the sum of its proper divisors (1).

123355001221 is an equidigital number, since it uses as much as digits as its factorization.

123355001221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 25.

Adding to 123355001221 its reverse (122100553321), we get a palindrome (245455554542).

The spelling of 123355001221 in words is "one hundred twenty-three billion, three hundred fifty-five million, one thousand, two hundred twenty-one".