218749837849 has 9 divisors (see below), whose sum is σ = 220756144063. Its totient is φ = 216761615392.

The previous prime is 218749837793. The next prime is 218749837861. The reversal of 218749837849 is 948738947812.

The square root of 218749837849 is 467707.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3854547225 + 214895290624 = 62085^2 + 463568^2 .

It is not a de Polignac number, because 218749837849 - 2¹⁹ = 218749313561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218749817849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 52848822 + ... + 52852960.

Almost surely, 2^218749837849 is an apocalyptic number.

218749837849 is the 467707-th square number.

218749837849 is the 233854-th centered octagonal number.

It is an amenable number.

218749837849 is a deficient number, since it is larger than the sum of its proper divisors (2006306214).

218749837849 is an frugal number, since it uses more digits than its factorization.

218749837849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8504 (or 4252 counting only the distinct ones).

The product of its digits is 195084288, while the sum is 70.

The spelling of 218749837849 in words is "two hundred eighteen billion, seven hundred forty-nine million, eight hundred thirty-seven thousand, eight hundred forty-nine".