21214036239817 has 2 divisors, whose sum is σ = 21214036239818. Its totient is φ = 21214036239816.

The previous prime is 21214036239811. The next prime is 21214036239827. The reversal of 21214036239817 is 71893263041212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14090533957696 + 7123502282121 = 3753736^2 + 2668989^2 .

It is a cyclic number.

It is not a de Polignac number, because 21214036239817 - 2¹¹ = 21214036237769 is a prime.

It is not a weakly prime, because it can be changed into another prime (21214036239811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10607018119908 + 10607018119909.

It is an arithmetic number, because the mean of its divisors is an integer number (10607018119909).

Almost surely, 2^{21214036239817} is an apocalyptic number.

It is an amenable number.

21214036239817 is a deficient number, since it is larger than the sum of its proper divisors (1).

21214036239817 is an equidigital number, since it uses as much as digits as its factorization.

21214036239817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 870912, while the sum is 49.

The spelling of 21214036239817 in words is "twenty-one trillion, two hundred fourteen billion, thirty-six million, two hundred thirty-nine thousand, eight hundred seventeen".