21216210516341 has 2 divisors, whose sum is σ = 21216210516342. Its totient is φ = 21216210516340.

The previous prime is 21216210516323. The next prime is 21216210516373. The reversal of 21216210516341 is 14361501261212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14004547330225 + 7211663186116 = 3742265^2 + 2685454^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21216210516341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21216210516541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10608105258170 + 10608105258171.

It is an arithmetic number, because the mean of its divisors is an integer number (10608105258171).

Almost surely, 2^{21216210516341} is an apocalyptic number.

It is an amenable number.

21216210516341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21216210516341 is an equidigital number, since it uses as much as digits as its factorization.

21216210516341 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

Adding to 21216210516341 its reverse (14361501261212), we get a palindrome (35577711777553).

The spelling of 21216210516341 in words is "twenty-one trillion, two hundred sixteen billion, two hundred ten million, five hundred sixteen thousand, three hundred forty-one".