21437838560209 has 8 divisors (see below), whose sum is σ = 22199318208360. Its totient is φ = 20677841834496.

The previous prime is 21437838560183. The next prime is 21437838560213. The reversal of 21437838560209 is 90206583873412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2908662030400 + 18529176529809 = 1705480^2 + 4304553^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21437838560209 - 2⁷ = 21437838560081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21437838560909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 370701184 + ... + 370759009.

It is an arithmetic number, because the mean of its divisors is an integer number (2774914776045).

It is a 1-persistent number, because it is pandigital, but 2⋅21437838560209 = 42875677120418 is not.

Almost surely, 2^{21437838560209} is an apocalyptic number.

21437838560209 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21437838560209 is a deficient number, since it is larger than the sum of its proper divisors (761479648151).

21437838560209 is an equidigital number, since it uses as much as digits as its factorization.

21437838560209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 741461219.

The product of its (nonzero) digits is 17418240, while the sum is 58.

The spelling of 21437838560209 in words is "twenty-one trillion, four hundred thirty-seven billion, eight hundred thirty-eight million, five hundred sixty thousand, two hundred nine".