21114120421 has 2 divisors, whose sum is σ = 21114120422. Its totient is φ = 21114120420.

The previous prime is 21114120407. The next prime is 21114120431. The reversal of 21114120421 is 12402141112.

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., 11987184196 + 9126936225 = 109486^2 + 95535^2 .

It is a cyclic number.

It is not a de Polignac number, because 21114120421 - 2¹¹ = 21114118373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21114120431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557060210 + 10557060211.

It is an arithmetic number, because the mean of its divisors is an integer number (10557060211).

Almost surely, 2^21114120421 is an apocalyptic number.

It is an amenable number.

21114120421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21114120421 is an equidigital number, since it uses as much as digits as its factorization.

21114120421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21114120421 its reverse (12402141112), we get a palindrome (33516261533).

The spelling of 21114120421 in words is "twenty-one billion, one hundred fourteen million, one hundred twenty thousand, four hundred twenty-one".