670391 has 8 divisors (see below), whose sum is σ = 698544. Its totient is φ = 642880.

The previous prime is 670379. The next prime is 670399. The reversal of 670391 is 193076.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-670391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 670391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (670399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3305 + ... + 3501.

It is an arithmetic number, because the mean of its divisors is an integer number (87318).

2⁶⁷⁰³⁹¹ is an apocalyptic number.

670391 is a deficient number, since it is larger than the sum of its proper divisors (28153).

670391 is a wasteful number, since it uses less digits than its factorization.

670391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 670391 is about 818.7740836153. The cubic root of 670391 is about 87.5204197241.

The spelling of 670391 in words is "six hundred seventy thousand, three hundred ninety-one".