671956009 has 4 divisors (see below), whose sum is σ = 673729360. Its totient is φ = 670182660.

The previous prime is 671956007. The next prime is 671956037. The reversal of 671956009 is 900659176.

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 671956009 - 2¹ = 671956007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671956007) 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, 886107 + ... + 886864.

It is an arithmetic number, because the mean of its divisors is an integer number (168432340).

Almost surely, 2^671956009 is an apocalyptic number.

It is an amenable number.

671956009 is a deficient number, since it is larger than the sum of its proper divisors (1773351).

671956009 is a wasteful number, since it uses less digits than its factorization.

671956009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1773350.

The product of its (nonzero) digits is 102060, while the sum is 43.

The square root of 671956009 is about 25922.1142849113. The cubic root of 671956009 is about 875.8847145222.

The spelling of 671956009 in words is "six hundred seventy-one million, nine hundred fifty-six thousand, nine".