671840 has 96 divisors (see below), whose sum is σ = 1905120. Its totient is φ = 221184.

The previous prime is 671837. The next prime is 671851. The reversal of 671840 is 48176.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35351 + ... + 35369.

It is an arithmetic number, because the mean of its divisors is an integer number (19845).

2⁶⁷¹⁸⁴⁰ 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 671840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (952560).

671840 is an abundant number, since it is smaller than the sum of its proper divisors (1233280).

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

671840 is a wasteful number, since it uses less digits than its factorization.

671840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 56 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 671840 is about 819.6584654599. The cubic root of 671840 is about 87.5834306283.

The spelling of 671840 in words is "six hundred seventy-one thousand, eight hundred forty".