21216565524463 has 2 divisors, whose sum is σ = 21216565524464. Its totient is φ = 21216565524462.

The previous prime is 21216565524461. The next prime is 21216565524523. The reversal of 21216565524463 is 36442556561212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21216565524463 - 2¹ = 21216565524461 is a prime.

Together with 21216565524461, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21216565524463.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21216565524461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10608282762231 + 10608282762232.

It is an arithmetic number, because the mean of its divisors is an integer number (10608282762232).

Almost surely, 2^{21216565524463} is an apocalyptic number.

21216565524463 is a deficient number, since it is larger than the sum of its proper divisors (1).

21216565524463 is an equidigital number, since it uses as much as digits as its factorization.

21216565524463 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368000, while the sum is 52.

The spelling of 21216565524463 in words is "twenty-one trillion, two hundred sixteen billion, five hundred sixty-five million, five hundred twenty-four thousand, four hundred sixty-three".