21216210530643 has 8 divisors (see below), whose sum is σ = 31431423008400. Its totient is φ = 14144140353744.

The previous prime is 21216210530639. The next prime is 21216210530653. The reversal of 21216210530643 is 34603501261212.

21216210530643 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 6 + 2 + 1 + 0 + 5 + 3 + 0 + 643 = 666.

It is not a de Polignac number, because 21216210530643 - 2² = 21216210530639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21216210530598 and 21216210530607.

It is not an unprimeable number, because it can be changed into a prime (21216210530623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392892787578 + ... + 392892787631.

It is an arithmetic number, because the mean of its divisors is an integer number (3928927876050).

Almost surely, 2^{21216210530643} is an apocalyptic number.

21216210530643 is a deficient number, since it is larger than the sum of its proper divisors (10215212477757).

21216210530643 is an equidigital number, since it uses as much as digits as its factorization.

21216210530643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785785575218 (or 785785575212 counting only the distinct ones).

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

Adding to 21216210530643 its reverse (34603501261212), we get a palindrome (55819711791855).

The spelling of 21216210530643 in words is "twenty-one trillion, two hundred sixteen billion, two hundred ten million, five hundred thirty thousand, six hundred forty-three".