21216416500323 has 72 divisors (see below), whose sum is σ = 37359650620656. Its totient is φ = 11465105126400.

The previous prime is 21216416500309. The next prime is 21216416500393. The reversal of 21216416500323 is 32300561461212.

21216416500323 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 641 + 6 + 5 + 0 + 0 + 3 + 2 + 3 = 666.

It is not a de Polignac number, because 21216416500323 - 2³⁶ = 21147697023587 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21216416500393) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 16852698 + ... + 18067823.

It is an arithmetic number, because the mean of its divisors is an integer number (518884036398).

Almost surely, 2^{21216416500323} is an apocalyptic number.

21216416500323 is a deficient number, since it is larger than the sum of its proper divisors (16143234120333).

21216416500323 is a wasteful number, since it uses less digits than its factorization.

21216416500323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34920593 (or 34920571 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

Adding to 21216416500323 its reverse (32300561461212), we get a palindrome (53516977961535).

The spelling of 21216416500323 in words is "twenty-one trillion, two hundred sixteen billion, four hundred sixteen million, five hundred thousand, three hundred twenty-three".