671968909 has 4 divisors (see below), whose sum is σ = 672748416. Its totient is φ = 671189404.

The previous prime is 671968903. The next prime is 671968919. The reversal of 671968909 is 909869176.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 671968909 - 2¹¹ = 671966861 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 671968909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671968903) 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, 388459 + ... + 390184.

It is an arithmetic number, because the mean of its divisors is an integer number (168187104).

Almost surely, 2^671968909 is an apocalyptic number.

It is an amenable number.

671968909 is a deficient number, since it is larger than the sum of its proper divisors (779507).

671968909 is an equidigital number, since it uses as much as digits as its factorization.

671968909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779506.

The product of its (nonzero) digits is 1469664, while the sum is 55.

The square root of 671968909 is about 25922.3631060133. The cubic root of 671968909 is about 875.8903194727.

The spelling of 671968909 in words is "six hundred seventy-one million, nine hundred sixty-eight thousand, nine hundred nine".