20430403421 has 2 divisors, whose sum is σ = 20430403422. Its totient is φ = 20430403420.

The previous prime is 20430403397. The next prime is 20430403439. The reversal of 20430403421 is 12430403402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16877647396 + 3552756025 = 129914^2 + 59605^2 .

It is a cyclic number.

It is not a de Polignac number, because 20430403421 - 2¹⁰ = 20430402397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20430403481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215201710 + 10215201711.

It is an arithmetic number, because the mean of its divisors is an integer number (10215201711).

Almost surely, 2^20430403421 is an apocalyptic number.

It is an amenable number.

20430403421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20430403421 is an equidigital number, since it uses as much as digits as its factorization.

20430403421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 20430403421 its reverse (12430403402), we get a palindrome (32860806823).

The spelling of 20430403421 in words is "twenty billion, four hundred thirty million, four hundred three thousand, four hundred twenty-one".