918744536221 has 2 divisors, whose sum is σ = 918744536222. Its totient is φ = 918744536220.

The previous prime is 918744536219. The next prime is 918744536249. The reversal of 918744536221 is 122635447819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 847346024196 + 71398512025 = 920514^2 + 267205^2 .

It is a cyclic number.

It is not a de Polignac number, because 918744536221 - 2¹ = 918744536219 is a prime.

Together with 918744536219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (918744536251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459372268110 + 459372268111.

It is an arithmetic number, because the mean of its divisors is an integer number (459372268111).

Almost surely, 2^918744536221 is an apocalyptic number.

It is an amenable number.

918744536221 is a deficient number, since it is larger than the sum of its proper divisors (1).

918744536221 is an equidigital number, since it uses as much as digits as its factorization.

918744536221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2903040, while the sum is 52.

The spelling of 918744536221 in words is "nine hundred eighteen billion, seven hundred forty-four million, five hundred thirty-six thousand, two hundred twenty-one".