671988 has 24 divisors (see below), whose sum is σ = 1622880. Its totient is φ = 216160.

The previous prime is 671981. The next prime is 671999. The reversal of 671988 is 889176.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671981) by changing a digit.

671988 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 618 + ... + 1313.

It is an arithmetic number, because the mean of its divisors is an integer number (67620).

2⁶⁷¹⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

671988 is an abundant number, since it is smaller than the sum of its proper divisors (950892).

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

671988 is a wasteful number, since it uses less digits than its factorization.

671988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1967 (or 1965 counting only the distinct ones).

The product of its digits is 24192, while the sum is 39.

The square root of 671988 is about 819.7487419935. The cubic root of 671988 is about 87.5898614233.

The spelling of 671988 in words is "six hundred seventy-one thousand, nine hundred eighty-eight".