84478 has 4 divisors (see below), whose sum is σ = 126720. Its totient is φ = 42238.

The previous prime is 84467. The next prime is 84481. The reversal of 84478 is 87448.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

84478 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21118 + ... + 21121.

It is an arithmetic number, because the mean of its divisors is an integer number (31680).

2⁸⁴⁴⁷⁸ is an apocalyptic number.

84478 is a deficient number, since it is larger than the sum of its proper divisors (42242).

84478 is a wasteful number, since it uses less digits than its factorization.

84478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42241.

The product of its digits is 7168, while the sum is 31.

The square root of 84478 is about 290.6509934612. The cubic root of 84478 is about 43.8781061537.

It can be divided in two parts, 8447 and 8, that multiplied together give a palindrome (67576).

The spelling of 84478 in words is "eighty-four thousand, four hundred seventy-eight".