218899021 has 8 divisors (see below), whose sum is σ = 252846144. Its totient is φ = 187293120.

The previous prime is 218899003. The next prime is 218899081. The reversal of 218899021 is 120998812.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218899021 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 (218899081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 585105 + ... + 585478.

It is an arithmetic number, because the mean of its divisors is an integer number (31605768).

Almost surely, 2^218899021 is an apocalyptic number.

It is an amenable number.

218899021 is a deficient number, since it is larger than the sum of its proper divisors (33947123).

218899021 is a wasteful number, since it uses less digits than its factorization.

218899021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1170611.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 218899021 is about 14795.2364293377. The cubic root of 218899021 is about 602.6723585325.

The spelling of 218899021 in words is "two hundred eighteen million, eight hundred ninety-nine thousand, twenty-one".