20404402123321 has 2 divisors, whose sum is σ = 20404402123322. Its totient is φ = 20404402123320.

The previous prime is 20404402123289. The next prime is 20404402123411. The reversal of 20404402123321 is 12332120440402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11715696752400 + 8688705370921 = 3422820^2 + 2947661^2 .

It is a cyclic number.

It is not a de Polignac number, because 20404402123321 - 2⁵ = 20404402123289 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20404402123321.

It is not a weakly prime, because it can be changed into another prime (20404402127321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10202201061660 + 10202201061661.

It is an arithmetic number, because the mean of its divisors is an integer number (10202201061661).

Almost surely, 2^{20404402123321} is an apocalyptic number.

It is an amenable number.

20404402123321 is a deficient number, since it is larger than the sum of its proper divisors (1).

20404402123321 is an equidigital number, since it uses as much as digits as its factorization.

20404402123321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 20404402123321 its reverse (12332120440402), we get a palindrome (32736522563723).

The spelling of 20404402123321 in words is "twenty trillion, four hundred four billion, four hundred two million, one hundred twenty-three thousand, three hundred twenty-one".