21342200221 has 2 divisors, whose sum is σ = 21342200222. Its totient is φ = 21342200220.

The previous prime is 21342200203. The next prime is 21342200237. The reversal of 21342200221 is 12200224312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13084843321 + 8257356900 = 114389^2 + 90870^2 .

It is a cyclic number.

It is not a de Polignac number, because 21342200221 - 2²¹ = 21340103069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21342200261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671100110 + 10671100111.

It is an arithmetic number, because the mean of its divisors is an integer number (10671100111).

Almost surely, 2^21342200221 is an apocalyptic number.

It is an amenable number.

21342200221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21342200221 is an equidigital number, since it uses as much as digits as its factorization.

21342200221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21342200221 its reverse (12200224312), we get a palindrome (33542424533).

The spelling of 21342200221 in words is "twenty-one billion, three hundred forty-two million, two hundred thousand, two hundred twenty-one".