21216361636412 has 6 divisors (see below), whose sum is σ = 37128632863728. Its totient is φ = 10608180818204.

The previous prime is 21216361636363. The next prime is 21216361636423. The reversal of 21216361636412 is 21463616361212.

It is a congruent number.

It is an unprimeable number.

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, 2652045204548 + ... + 2652045204555.

It is an arithmetic number, because the mean of its divisors is an integer number (6188105477288).

Almost surely, 2^{21216361636412} is an apocalyptic number.

It is an amenable number.

21216361636412 is a deficient number, since it is larger than the sum of its proper divisors (15912271227316).

21216361636412 is a wasteful number, since it uses less digits than its factorization.

21216361636412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5304090409107 (or 5304090409105 counting only the distinct ones).

The product of its digits is 373248, while the sum is 44.

Adding to 21216361636412 its reverse (21463616361212), we get a palindrome (42679977997624).

The spelling of 21216361636412 in words is "twenty-one trillion, two hundred sixteen billion, three hundred sixty-one million, six hundred thirty-six thousand, four hundred twelve".