670405 has 4 divisors (see below), whose sum is σ = 804492. Its totient is φ = 536320.

The previous prime is 670399. The next prime is 670409. The reversal of 670405 is 504076.

670405 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 can be written as a sum of positive squares in 2 ways, for example, as 199809 + 470596 = 447^2 + 686^2 .

It is not a de Polignac number, because 670405 - 2¹⁹ = 146117 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (670409) 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, 67036 + ... + 67045.

It is an arithmetic number, because the mean of its divisors is an integer number (201123).

2⁶⁷⁰⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

670405 is a deficient number, since it is larger than the sum of its proper divisors (134087).

670405 is a wasteful number, since it uses less digits than its factorization.

670405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134086.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 670405 is about 818.7826329375. The cubic root of 670405 is about 87.5210289593.

The spelling of 670405 in words is "six hundred seventy thousand, four hundred five".