21412221409 has 2 divisors, whose sum is σ = 21412221410. Its totient is φ = 21412221408.

The previous prime is 21412221407. The next prime is 21412221421. The reversal of 21412221409 is 90412221412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18428877009 + 2983344400 = 135753^2 + 54620^2 .

It is a cyclic number.

It is not a de Polignac number, because 21412221409 - 2¹ = 21412221407 is a prime.

Together with 21412221407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21412221401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10706110704 + 10706110705.

It is an arithmetic number, because the mean of its divisors is an integer number (10706110705).

Almost surely, 2^21412221409 is an apocalyptic number.

It is an amenable number.

21412221409 is a deficient number, since it is larger than the sum of its proper divisors (1).

21412221409 is an equidigital number, since it uses as much as digits as its factorization.

21412221409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 28.

The spelling of 21412221409 in words is "twenty-one billion, four hundred twelve million, two hundred twenty-one thousand, four hundred nine".