218896722509 has 2 divisors, whose sum is σ = 218896722510. Its totient is φ = 218896722508.

The previous prime is 218896722493. The next prime is 218896722557. The reversal of 218896722509 is 905227698812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191664462025 + 27232260484 = 437795^2 + 165022^2 .

It is a cyclic number.

It is not a de Polignac number, because 218896722509 - 2⁴ = 218896722493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218896722559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109448361254 + 109448361255.

It is an arithmetic number, because the mean of its divisors is an integer number (109448361255).

Almost surely, 2^218896722509 is an apocalyptic number.

It is an amenable number.

218896722509 is a deficient number, since it is larger than the sum of its proper divisors (1).

218896722509 is an equidigital number, since it uses as much as digits as its factorization.

218896722509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8709120, while the sum is 59.

The spelling of 218896722509 in words is "two hundred eighteen billion, eight hundred ninety-six million, seven hundred twenty-two thousand, five hundred nine".