638418 has 32 divisors (see below), whose sum is σ = 1477440. Its totient is φ = 181760.

The previous prime is 638371. The next prime is 638423. The reversal of 638418 is 814836.

It is a happy number.

It is an unprimeable number.

638418 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 838 + ... + 1406.

It is an arithmetic number, because the mean of its divisors is an integer number (46170).

2⁶³⁸⁴¹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638418, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (738720).

638418 is an abundant number, since it is smaller than the sum of its proper divisors (839022).

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

638418 is a wasteful number, since it uses less digits than its factorization.

638418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602.

The product of its digits is 4608, while the sum is 30.

The square root of 638418 is about 799.0106382271. The cubic root of 638418 is about 86.1063224377.

The spelling of 638418 in words is "six hundred thirty-eight thousand, four hundred eighteen".