628840 has 32 divisors (see below), whose sum is σ = 1440000. Its totient is φ = 247104.

The previous prime is 628819. The next prime is 628841. The reversal of 628840 is 48826.

It is a junction number, because it is equal to n+sod(n) for n = 628799 and 628808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3061 + ... + 3259.

It is an arithmetic number, because the mean of its divisors is an integer number (45000).

2⁶²⁸⁸⁴⁰ 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 628840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (720000).

628840 is an abundant number, since it is smaller than the sum of its proper divisors (811160).

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

628840 is a wasteful number, since it uses less digits than its factorization.

628840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 628840 is about 792.9943253265. The cubic root of 628840 is about 85.6735414819.

It can be divided in two parts, 6288 and 40, that added together give a triangular number (6328 = T₁₁₂).

The spelling of 628840 in words is "six hundred twenty-eight thousand, eight hundred forty".