218402128 has 80 divisors (see below), whose sum is σ = 515217024. Its totient is φ = 87552000.

The previous prime is 218402123. The next prime is 218402141. The reversal of 218402128 is 821204812.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 218402096 and 218402105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218402123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 477676 + ... + 478132.

Almost surely, 2^218402128 is an apocalyptic number.

218402128 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 218402128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (257608512).

218402128 is an abundant number, since it is smaller than the sum of its proper divisors (296814896).

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

218402128 is a wasteful number, since it uses less digits than its factorization.

218402128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740 (or 734 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 218402128 is about 14778.4345585045. The cubic root of 218402128 is about 602.2159981040.

The spelling of 218402128 in words is "two hundred eighteen million, four hundred two thousand, one hundred twenty-eight".