21414435421 has 2 divisors, whose sum is σ = 21414435422. Its totient is φ = 21414435420.

The previous prime is 21414435401. The next prime is 21414435473. The reversal of 21414435421 is 12453441412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21275431321 + 139004100 = 145861^2 + 11790^2 .

It is a cyclic number.

It is not a de Polignac number, because 21414435421 - 2⁷ = 21414435293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21414435401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10707217710 + 10707217711.

It is an arithmetic number, because the mean of its divisors is an integer number (10707217711).

Almost surely, 2^21414435421 is an apocalyptic number.

It is an amenable number.

21414435421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21414435421 is an equidigital number, since it uses as much as digits as its factorization.

21414435421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15360, while the sum is 31.

Adding to 21414435421 its reverse (12453441412), we get a palindrome (33867876833).

The spelling of 21414435421 in words is "twenty-one billion, four hundred fourteen million, four hundred thirty-five thousand, four hundred twenty-one".