20404424213 has 2 divisors, whose sum is σ = 20404424214. Its totient is φ = 20404424212.

The previous prime is 20404424143. The next prime is 20404424219. The reversal of 20404424213 is 31242440402.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19210514404 + 1193909809 = 138602^2 + 34553^2 .

It is a cyclic number.

It is not a de Polignac number, because 20404424213 - 2¹⁸ = 20404162069 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20404424219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10202212106 + 10202212107.

It is an arithmetic number, because the mean of its divisors is an integer number (10202212107).

Almost surely, 2^20404424213 is an apocalyptic number.

It is an amenable number.

20404424213 is a deficient number, since it is larger than the sum of its proper divisors (1).

20404424213 is an equidigital number, since it uses as much as digits as its factorization.

20404424213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 20404424213 its reverse (31242440402), we get a palindrome (51646864615).

The spelling of 20404424213 in words is "twenty billion, four hundred four million, four hundred twenty-four thousand, two hundred thirteen".