978444 has 18 divisors (see below), whose sum is σ = 2473380. Its totient is φ = 326136.

The previous prime is 978427. The next prime is 978449. The reversal of 978444 is 444879.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×978444² = 1914705322272, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 27179 = 978444 / (9 + 7 + 8 + 4 + 4 + 4).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 978399 and 978408.

It is not an unprimeable number, because it can be changed into a prime (978449) by changing a digit.

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 in 5 ways as a sum of consecutive naturals, for example, 13554 + ... + 13625.

It is an arithmetic number, because the mean of its divisors is an integer number (137410).

2⁹⁷⁸⁴⁴⁴ is an apocalyptic number.

It is an amenable number.

978444 is an abundant number, since it is smaller than the sum of its proper divisors (1494936).

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

978444 is a wasteful number, since it uses less digits than its factorization.

978444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27189 (or 27184 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 978444 is about 989.1632827799. The cubic root of 978444 is about 99.2762410337.

The spelling of 978444 in words is "nine hundred seventy-eight thousand, four hundred forty-four".