21216602336044 has 12 divisors (see below), whose sum is σ = 39313116093384. Its totient is φ = 9984283452224.

The previous prime is 21216602335997. The next prime is 21216602336047. The reversal of 21216602336044 is 44063320661212.

It is a junction number, because it is equal to n+sod(n) for n = 21216602335988 and 21216602336006.

It is not an unprimeable number, because it can be changed into a prime (21216602336047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156004428874 + ... + 156004429009.

It is an arithmetic number, because the mean of its divisors is an integer number (3276093007782).

Almost surely, 2^{21216602336044} is an apocalyptic number.

It is an amenable number.

21216602336044 is a deficient number, since it is larger than the sum of its proper divisors (18096513757340).

21216602336044 is a wasteful number, since it uses less digits than its factorization.

21216602336044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312008857904 (or 312008857902 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 40.

Adding to 21216602336044 its reverse (44063320661212), we get a palindrome (65279922997256).

The spelling of 21216602336044 in words is "twenty-one trillion, two hundred sixteen billion, six hundred two million, three hundred thirty-six thousand, forty-four".