400218 has 32 divisors (see below), whose sum is σ = 986496. Its totient is φ = 105408.

The previous prime is 400217. The next prime is 400237. The reversal of 400218 is 812004.

It is a junction number, because it is equal to n+sod(n) for n = 400197 and 400206.

It is not an unprimeable number, because it can be changed into a prime (400217) 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, 180 + ... + 912.

It is an arithmetic number, because the mean of its divisors is an integer number (30828).

2⁴⁰⁰²¹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (493248).

400218 is an abundant number, since it is smaller than the sum of its proper divisors (586278).

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

400218 is a wasteful number, since it uses less digits than its factorization.

400218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 400218 is about 632.6278526907. The cubic root of 400218 is about 73.6940128563.

The spelling of 400218 in words is "four hundred thousand, two hundred eighteen".