671538 has 32 divisors (see below), whose sum is σ = 1566720. Its totient is φ = 187920.

The previous prime is 671537. The next prime is 671557. The reversal of 671538 is 835176.

It is not an unprimeable number, because it can be changed into a prime (671533) 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 15 ways as a sum of consecutive naturals, for example, 2343 + ... + 2613.

It is an arithmetic number, because the mean of its divisors is an integer number (48960).

2⁶⁷¹⁵³⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 671538, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (783360).

671538 is an abundant number, since it is smaller than the sum of its proper divisors (895182).

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

671538 is a wasteful number, since it uses less digits than its factorization.

671538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342.

The product of its digits is 5040, while the sum is 30.

The square root of 671538 is about 819.4742216812. The cubic root of 671538 is about 87.5703053999.

It can be divided in two parts, 67153 and 8, that added together give a triangular number (67161 = T₃₆₆).

The spelling of 671538 in words is "six hundred seventy-one thousand, five hundred thirty-eight".