671904 has 36 divisors (see below), whose sum is σ = 1911546. Its totient is φ = 223872.

The previous prime is 671903. The next prime is 671911. The reversal of 671904 is 409176.

It can be written as a sum of positive squares in only one way, i.e., 608400 + 63504 = 780^2 + 252^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (671903) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 879 + ... + 1454.

2⁶⁷¹⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

671904 is an abundant number, since it is smaller than the sum of its proper divisors (1239642).

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

671904 is a wasteful number, since it uses less digits than its factorization.

671904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2349 (or 2338 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 671904 is about 819.6975051810. The cubic root of 671904 is about 87.5862116285.

The spelling of 671904 in words is "six hundred seventy-one thousand, nine hundred four".