20404000522421 has 2 divisors, whose sum is σ = 20404000522422. Its totient is φ = 20404000522420.

The previous prime is 20404000522417. The next prime is 20404000522457. The reversal of 20404000522421 is 12422500040402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10286702729521 + 10117297792900 = 3207289^2 + 3180770^2 .

It is a cyclic number.

It is not a de Polignac number, because 20404000522421 - 2² = 20404000522417 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20404000522121) 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, 10202000261210 + 10202000261211.

It is an arithmetic number, because the mean of its divisors is an integer number (10202000261211).

Almost surely, 2^{20404000522421} is an apocalyptic number.

It is an amenable number.

20404000522421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20404000522421 is an equidigital number, since it uses as much as digits as its factorization.

20404000522421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5120, while the sum is 26.

Adding to 20404000522421 its reverse (12422500040402), we get a palindrome (32826500562823).

The spelling of 20404000522421 in words is "twenty trillion, four hundred four billion, five hundred twenty-two thousand, four hundred twenty-one".