398 can be written using four 4's:
See also 113
398 has 4
divisors (see below), whose sum is σ = 600
Its totient is φ = 198
The previous prime is 397. The next prime is 401. The reversal of 398 is 893.
398 is nontrivially palindromic in base 8 and base 12.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 893 = 19 ⋅47.
It is a magnanimous number.
398 is an undulating number in base 8 and base 12.
It is a Curzon number.
It is a plaindrome in base 13 and base 16.
It is a nialpdrome in base 11.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (397) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (5) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98 + ... + 101.
It is an arithmetic number, because the mean of its divisors is an integer number (150).
398 is a deficient number, since it is larger than the sum of its proper divisors (202).
398 is a wasteful number, since it uses less digits than its factorization.
398 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 201.
The product of its digits is 216, while the sum is 20.
The square root of 398 is about 19.9499373433.
The cubic root of 398 is about 7.3557623684.
Subtracting from 398 its sum of digits (20), we obtain a triangular number (378 = T27).
It can be divided in two parts, 3 and 98, that added together give a palindrome (101).
The spelling of 398 in words is "three hundred ninety-eight", and thus it is an aban number and an oban number.