21337216606837 has 2 divisors, whose sum is σ = 21337216606838. Its totient is φ = 21337216606836.

The previous prime is 21337216606751. The next prime is 21337216606847. The reversal of 21337216606837 is 73860661273312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11444140960561 + 9893075646276 = 3382919^2 + 3145326^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21337216606837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21337216606847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10668608303418 + 10668608303419.

It is an arithmetic number, because the mean of its divisors is an integer number (10668608303419).

Almost surely, 2^{21337216606837} is an apocalyptic number.

It is an amenable number.

21337216606837 is a deficient number, since it is larger than the sum of its proper divisors (1).

21337216606837 is an equidigital number, since it uses as much as digits as its factorization.

21337216606837 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9144576, while the sum is 55.

The spelling of 21337216606837 in words is "twenty-one trillion, three hundred thirty-seven billion, two hundred sixteen million, six hundred six thousand, eight hundred thirty-seven".