670891 has 4 divisors (see below), whose sum is σ = 722512. Its totient is φ = 619272.

The previous prime is 670877. The next prime is 670897. The reversal of 670891 is 198076.

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

It is a cyclic number.

It is not a de Polignac number, because 670891 - 2⁷ = 670763 is a prime.

It is a Duffinian number.

670891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (670897) 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 3 ways as a sum of consecutive naturals, for example, 25791 + ... + 25816.

It is an arithmetic number, because the mean of its divisors is an integer number (180628).

2⁶⁷⁰⁸⁹¹ is an apocalyptic number.

670891 is a deficient number, since it is larger than the sum of its proper divisors (51621).

670891 is a wasteful number, since it uses less digits than its factorization.

670891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51620.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 670891 is about 819.0793612343. The cubic root of 670891 is about 87.5421728677.

The spelling of 670891 in words is "six hundred seventy thousand, eight hundred ninety-one".