21216215264593 has 2 divisors, whose sum is σ = 21216215264594. Its totient is φ = 21216215264592.

The previous prime is 21216215264539. The next prime is 21216215264603. The reversal of 21216215264593 is 39546251261212.

Together with previous prime (21216215264539) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10733073642769 + 10483141621824 = 3276137^2 + 3237768^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21216215264593 is a prime.

It is not a weakly prime, because it can be changed into another prime (21216215265593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10608107632296 + 10608107632297.

It is an arithmetic number, because the mean of its divisors is an integer number (10608107632297).

Almost surely, 2^{21216215264593} is an apocalyptic number.

It is an amenable number.

21216215264593 is a deficient number, since it is larger than the sum of its proper divisors (1).

21216215264593 is an equidigital number, since it uses as much as digits as its factorization.

21216215264593 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1555200, while the sum is 49.

The spelling of 21216215264593 in words is "twenty-one trillion, two hundred sixteen billion, two hundred fifteen million, two hundred sixty-four thousand, five hundred ninety-three".