684438144 has 128 divisors (see below), whose sum is σ = 1972010880. Its totient is φ = 209080320.

The previous prime is 684438137. The next prime is 684438149. The reversal of 684438144 is 441834486.

It is a tau number, because it is divible by the number of its divisors (128).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 684438096 and 684438105.

It is not an unprimeable number, because it can be changed into a prime (684438149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 833254 + ... + 834074.

It is an arithmetic number, because the mean of its divisors is an integer number (15406335).

Almost surely, 2^684438144 is an apocalyptic number.

684438144 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684438144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (986005440).

684438144 is an abundant number, since it is smaller than the sum of its proper divisors (1287572736).

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

684438144 is a wasteful number, since it uses less digits than its factorization.

684438144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1018 (or 1006 counting only the distinct ones).

The product of its digits is 294912, while the sum is 42.

The square root of 684438144 is about 26161.7687475446. The cubic root of 684438144 is about 881.2749014039.

The spelling of 684438144 in words is "six hundred eighty-four million, four hundred thirty-eight thousand, one hundred forty-four".