678399444 has 72 divisors (see below), whose sum is σ = 1798917120. Its totient is φ = 215151552.

The previous prime is 678399437. The next prime is 678399461. The reversal of 678399444 is 444993876.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 161037 + ... + 165195.

It is an arithmetic number, because the mean of its divisors is an integer number (24984960).

Almost surely, 2^678399444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 678399444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899458560).

678399444 is an abundant number, since it is smaller than the sum of its proper divisors (1120517676).

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

678399444 is a wasteful number, since it uses less digits than its factorization.

678399444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4389 (or 4384 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 54.

The square root of 678399444 is about 26046.1022803797. The cubic root of 678399444 is about 878.6754539640.

The spelling of 678399444 in words is "six hundred seventy-eight million, three hundred ninety-nine thousand, four hundred forty-four".