21342002021 has 2 divisors, whose sum is σ = 21342002022. Its totient is φ = 21342002020.

The previous prime is 21342001963. The next prime is 21342002023. The reversal of 21342002021 is 12020024312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16116302500 + 5225699521 = 126950^2 + 72289^2 .

It is a cyclic number.

It is not a de Polignac number, because 21342002021 - 2³⁰ = 20268260197 is a prime.

Together with 21342002023, 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 (21342002023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671001010 + 10671001011.

It is an arithmetic number, because the mean of its divisors is an integer number (10671001011).

Almost surely, 2^21342002021 is an apocalyptic number.

It is an amenable number.

21342002021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21342002021 is an equidigital number, since it uses as much as digits as its factorization.

21342002021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21342002021 its reverse (12020024312), we get a palindrome (33362026333).

The spelling of 21342002021 in words is "twenty-one billion, three hundred forty-two million, two thousand, twenty-one".