21216211413616 has 10 divisors (see below), whose sum is σ = 41106409613912. Its totient is φ = 10608105706800.

The previous prime is 21216211413611. The next prime is 21216211413623. The reversal of 21216211413616 is 61631411261212.

It is a super-4 number, since 4×21216211413616⁴ (a number of 54 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21216211413611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663006606660 + ... + 663006606691.

Almost surely, 2^{21216211413616} is an apocalyptic number.

It is an amenable number.

21216211413616 is a deficient number, since it is larger than the sum of its proper divisors (19890198200296).

21216211413616 is a wasteful number, since it uses less digits than its factorization.

21216211413616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326013213359 (or 1326013213353 counting only the distinct ones).

The product of its digits is 20736, while the sum is 37.

Adding to 21216211413616 its reverse (61631411261212), we get a palindrome (82847622674828).

The spelling of 21216211413616 in words is "twenty-one trillion, two hundred sixteen billion, two hundred eleven million, four hundred thirteen thousand, six hundred sixteen".