671491 has 4 divisors (see below), whose sum is σ = 693184. Its totient is φ = 649800.

The previous prime is 671477. The next prime is 671501. The reversal of 671491 is 194176.

671491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10800 + ... + 10861.

It is an arithmetic number, because the mean of its divisors is an integer number (173296).

2⁶⁷¹⁴⁹¹ is an apocalyptic number.

671491 is a deficient number, since it is larger than the sum of its proper divisors (21693).

671491 is a wasteful number, since it uses less digits than its factorization.

671491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21692.

The product of its digits is 1512, while the sum is 28.

The square root of 671491 is about 819.4455442554. The cubic root of 671491 is about 87.5682623781.

The spelling of 671491 in words is "six hundred seventy-one thousand, four hundred ninety-one".