21442312321 has 2 divisors, whose sum is σ = 21442312322. Its totient is φ = 21442312320.

The previous prime is 21442312303. The next prime is 21442312351. The reversal of 21442312321 is 12321324412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16011359296 + 5430953025 = 126536^2 + 73695^2 .

It is a cyclic number.

It is not a de Polignac number, because 21442312321 - 2⁹ = 21442311809 is a prime.

It is not a weakly prime, because it can be changed into another prime (21442312301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10721156160 + 10721156161.

It is an arithmetic number, because the mean of its divisors is an integer number (10721156161).

Almost surely, 2^21442312321 is an apocalyptic number.

It is an amenable number.

21442312321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21442312321 is an equidigital number, since it uses as much as digits as its factorization.

21442312321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 25.

Adding to 21442312321 its reverse (12321324412), we get a palindrome (33763636733).

The spelling of 21442312321 in words is "twenty-one billion, four hundred forty-two million, three hundred twelve thousand, three hundred twenty-one".