21216420365143 has 2 divisors, whose sum is σ = 21216420365144. Its totient is φ = 21216420365142.

The previous prime is 21216420365131. The next prime is 21216420365191. The reversal of 21216420365143 is 34156302461212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21216420365143 - 2²⁵ = 21216386810711 is a prime.

It is a super-2 number, since 2×21216420365143² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21216420365096 and 21216420365105.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21216420363143) 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, 10608210182571 + 10608210182572.

It is an arithmetic number, because the mean of its divisors is an integer number (10608210182572).

Almost surely, 2^{21216420365143} is an apocalyptic number.

21216420365143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21216420365143 is an equidigital number, since it uses as much as digits as its factorization.

21216420365143 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 21216420365143 in words is "twenty-one trillion, two hundred sixteen billion, four hundred twenty million, three hundred sixty-five thousand, one hundred forty-three".