218023989 has 8 divisors (see below), whose sum is σ = 290968992. Its totient is φ = 145214160.

The previous prime is 218023987. The next prime is 218023991. The reversal of 218023989 is 989320812.

It is an interprime number because it is at equal distance from previous prime (218023987) and next prime (218023991).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 218023989 - 2¹ = 218023987 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 218023989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218023987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29967 + ... + 36524.

It is an arithmetic number, because the mean of its divisors is an integer number (36371124).

Almost surely, 2^218023989 is an apocalyptic number.

It is an amenable number.

218023989 is a deficient number, since it is larger than the sum of its proper divisors (72945003).

218023989 is a wasteful number, since it uses less digits than its factorization.

218023989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67587.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 218023989 is about 14765.6354079328. The cubic root of 218023989 is about 601.8682406460.

The spelling of 218023989 in words is "two hundred eighteen million, twenty-three thousand, nine hundred eighty-nine".