20434421123 has 2 divisors, whose sum is σ = 20434421124. Its totient is φ = 20434421122.

The previous prime is 20434421081. The next prime is 20434421143. The reversal of 20434421123 is 32112443402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20434421123 - 2²⁴ = 20417643907 is a prime.

It is a super-2 number, since 2×20434421123² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 20434421092 and 20434421101.

It is not a weakly prime, because it can be changed into another prime (20434421143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10217210561 + 10217210562.

It is an arithmetic number, because the mean of its divisors is an integer number (10217210562).

Almost surely, 2^20434421123 is an apocalyptic number.

20434421123 is a deficient number, since it is larger than the sum of its proper divisors (1).

20434421123 is an equidigital number, since it uses as much as digits as its factorization.

20434421123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 20434421123 its reverse (32112443402), we get a palindrome (52546864525).

The spelling of 20434421123 in words is "twenty billion, four hundred thirty-four million, four hundred twenty-one thousand, one hundred twenty-three".