20345884421 has 2 divisors, whose sum is σ = 20345884422. Its totient is φ = 20345884420.

The previous prime is 20345884369. The next prime is 20345884423. The reversal of 20345884421 is 12448854302.

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., 20345884321 + 100 = 142639^2 + 10^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20345884421 is a prime.

Together with 20345884423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20345884423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10172942210 + 10172942211.

It is an arithmetic number, because the mean of its divisors is an integer number (10172942211).

Almost surely, 2^20345884421 is an apocalyptic number.

It is an amenable number.

20345884421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20345884421 is an equidigital number, since it uses as much as digits as its factorization.

20345884421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 245760, while the sum is 41.

The spelling of 20345884421 in words is "twenty billion, three hundred forty-five million, eight hundred eighty-four thousand, four hundred twenty-one".