218134728 has 128 divisors (see below), whose sum is σ = 700704000. Its totient is φ = 61585920.

The previous prime is 218134727. The next prime is 218134733. The reversal of 218134728 is 827431812.

218134728 is a `hidden beast` number, since 2 + 181 + 3 + 472 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 218134692 and 218134701.

It is not an unprimeable number, because it can be changed into a prime (218134727) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133758 + ... + 135378.

It is an arithmetic number, because the mean of its divisors is an integer number (5474250).

Almost surely, 2^218134728 is an apocalyptic number.

218134728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218134728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (350352000).

218134728 is an abundant number, since it is smaller than the sum of its proper divisors (482569272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218134728 is a wasteful number, since it uses less digits than its factorization.

218134728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732 (or 1722 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 218134728 is about 14769.3848213120. The cubic root of 218134728 is about 601.9701239391.

The spelling of 218134728 in words is "two hundred eighteen million, one hundred thirty-four thousand, seven hundred twenty-eight".