218007989 has 4 divisors (see below), whose sum is σ = 218514240. Its totient is φ = 217501740.

The previous prime is 218007967. The next prime is 218007991. The reversal of 218007989 is 989700812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 218007989 - 2⁸ = 218007733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218007089) 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 3 ways as a sum of consecutive naturals, for example, 252479 + ... + 253340.

It is an arithmetic number, because the mean of its divisors is an integer number (54628560).

Almost surely, 2^218007989 is an apocalyptic number.

It is an amenable number.

218007989 is a deficient number, since it is larger than the sum of its proper divisors (506251).

218007989 is an equidigital number, since it uses as much as digits as its factorization.

218007989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506250.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 218007989 is about 14765.0935994324. The cubic root of 218007989 is about 601.8535173006.

The spelling of 218007989 in words is "two hundred eighteen million, seven thousand, nine hundred eighty-nine".