218028661 has 8 divisors (see below), whose sum is σ = 228533760. Its totient is φ = 207609072.

The previous prime is 218028631. The next prime is 218028683. The reversal of 218028661 is 166820812.

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

It is a cyclic number.

It is not a de Polignac number, because 218028661 - 2¹³ = 218020469 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 (218028631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16126 + ... + 26383.

It is an arithmetic number, because the mean of its divisors is an integer number (28566720).

Almost surely, 2^218028661 is an apocalyptic number.

It is an amenable number.

218028661 is a deficient number, since it is larger than the sum of its proper divisors (10505099).

218028661 is a wasteful number, since it uses less digits than its factorization.

218028661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42755.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 218028661 is about 14765.7936122648. The cubic root of 218028661 is about 601.8725397269.

The spelling of 218028661 in words is "two hundred eighteen million, twenty-eight thousand, six hundred sixty-one".