671305840 has 20 divisors (see below), whose sum is σ = 1560786264. Its totient is φ = 268522304.

The previous prime is 671305819. The next prime is 671305847. The reversal of 671305840 is 48503176.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 671305796 and 671305805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671305847) 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, 4195582 + ... + 4195741.

Almost surely, 2^671305840 is an apocalyptic number.

It is an amenable number.

671305840 is an abundant number, since it is smaller than the sum of its proper divisors (889480424).

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

671305840 is a wasteful number, since it uses less digits than its factorization.

671305840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8391336 (or 8391330 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 671305840 is about 25909.5704325641. The cubic root of 671305840 is about 875.6021281377.

The spelling of 671305840 in words is "six hundred seventy-one million, three hundred five thousand, eight hundred forty".