218728899 has 12 divisors (see below), whose sum is σ = 316228536. Its totient is φ = 145686912.

The previous prime is 218728897. The next prime is 218728921. The reversal of 218728899 is 998827812.

It is not a de Polignac number, because 218728899 - 2¹ = 218728897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (218728897) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19 + ... + 20915.

It is an arithmetic number, because the mean of its divisors is an integer number (26352378).

Almost surely, 2^218728899 is an apocalyptic number.

218728899 is a deficient number, since it is larger than the sum of its proper divisors (97499637).

218728899 is a wasteful number, since it uses less digits than its factorization.

218728899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22066 (or 22063 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The square root of 218728899 is about 14789.4860965485. The cubic root of 218728899 is about 602.5161915496.

The spelling of 218728899 in words is "two hundred eighteen million, seven hundred twenty-eight thousand, eight hundred ninety-nine".