20420421433 has 2 divisors, whose sum is σ = 20420421434. Its totient is φ = 20420421432.

The previous prime is 20420421367. The next prime is 20420421443. The reversal of 20420421433 is 33412402402.

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., 11523593104 + 8896828329 = 107348^2 + 94323^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20420421433 is a prime.

It is a super-2 number, since 2×20420421433² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20420421398 and 20420421407.

It is not a weakly prime, because it can be changed into another prime (20420421443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210210716 + 10210210717.

It is an arithmetic number, because the mean of its divisors is an integer number (10210210717).

Almost surely, 2^20420421433 is an apocalyptic number.

It is an amenable number.

20420421433 is a deficient number, since it is larger than the sum of its proper divisors (1).

20420421433 is an equidigital number, since it uses as much as digits as its factorization.

20420421433 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 20420421433 its reverse (33412402402), we get a palindrome (53832823835).

The spelling of 20420421433 in words is "twenty billion, four hundred twenty million, four hundred twenty-one thousand, four hundred thirty-three".