671640211 has 4 divisors (see below), whose sum is σ = 732698424. Its totient is φ = 610582000.

The previous prime is 671640187. The next prime is 671640217. The reversal of 671640211 is 112046176.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 671640211 - 2¹⁹ = 671115923 is a prime.

It is a super-2 number, since 2×671640211² = 902201146064249042, which contains 22 as substring.

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 671640211.

It is not an unprimeable number, because it can be changed into a prime (671640217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30529090 + ... + 30529111.

It is an arithmetic number, because the mean of its divisors is an integer number (183174606).

Almost surely, 2^671640211 is an apocalyptic number.

671640211 is a deficient number, since it is larger than the sum of its proper divisors (61058213).

671640211 is a wasteful number, since it uses less digits than its factorization.

671640211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61058212.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 671640211 is about 25916.0222835218. The cubic root of 671640211 is about 875.7474803480.

Adding to 671640211 its reverse (112046176), we get a palindrome (783686387).

The spelling of 671640211 in words is "six hundred seventy-one million, six hundred forty thousand, two hundred eleven".