218103809 has 16 divisors (see below), whose sum is σ = 281301120. Its totient is φ = 164088960.

The previous prime is 218103799. The next prime is 218103811. The reversal of 218103809 is 908301812.

It is not a de Polignac number, because 218103809 - 2⁸ = 218103553 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (218103859) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46604 + ... + 51069.

It is an arithmetic number, because the mean of its divisors is an integer number (17581320).

It is a Proth number, since it is equal to 13 ⋅ 2²⁴ + 1 and 13 < 2²⁴.

Almost surely, 2^218103809 is an apocalyptic number.

218103809 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

218103809 is a deficient number, since it is larger than the sum of its proper divisors (63197311).

218103809 is a wasteful number, since it uses less digits than its factorization.

218103809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97720.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 218103809 is about 14768.3380581567. The cubic root of 218103809 is about 601.9416809765.

The spelling of 218103809 in words is "two hundred eighteen million, one hundred three thousand, eight hundred nine".