21522014321 has 2 divisors, whose sum is σ = 21522014322. Its totient is φ = 21522014320.

The previous prime is 21522014303. The next prime is 21522014329. The reversal of 21522014321 is 12341022512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14705200225 + 6816814096 = 121265^2 + 82564^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522014321 - 2³⁰ = 20448272497 is a prime.

It is not a weakly prime, because it can be changed into another prime (21522014329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761007160 + 10761007161.

It is an arithmetic number, because the mean of its divisors is an integer number (10761007161).

Almost surely, 2^21522014321 is an apocalyptic number.

It is an amenable number.

21522014321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21522014321 is an equidigital number, since it uses as much as digits as its factorization.

21522014321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21522014321 its reverse (12341022512), we get a palindrome (33863036833).

The spelling of 21522014321 in words is "twenty-one billion, five hundred twenty-two million, fourteen thousand, three hundred twenty-one".