21365334041237 has 2 divisors, whose sum is σ = 21365334041238. Its totient is φ = 21365334041236.

The previous prime is 21365334041167. The next prime is 21365334041263. The reversal of 21365334041237 is 73214043356312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21358391652196 + 6942389041 = 4621514^2 + 83321^2 .

It is a cyclic number.

It is not a de Polignac number, because 21365334041237 - 2¹⁰ = 21365334040213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21365334041267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682667020618 + 10682667020619.

It is an arithmetic number, because the mean of its divisors is an integer number (10682667020619).

Almost surely, 2^{21365334041237} is an apocalyptic number.

It is an amenable number.

21365334041237 is a deficient number, since it is larger than the sum of its proper divisors (1).

21365334041237 is an equidigital number, since it uses as much as digits as its factorization.

21365334041237 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1088640, while the sum is 44.

Adding to 21365334041237 its reverse (73214043356312), we get a palindrome (94579377397549).

The spelling of 21365334041237 in words is "twenty-one trillion, three hundred sixty-five billion, three hundred thirty-four million, forty-one thousand, two hundred thirty-seven".