667871811 has 20 divisors (see below), whose sum is σ = 1001598312. Its totient is φ = 443501568.

The previous prime is 667871807. The next prime is 667871819. The reversal of 667871811 is 118178766.

It is a happy number.

It is not a de Polignac number, because 667871811 - 2² = 667871807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (667871819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4776 + ... + 36858.

Almost surely, 2^667871811 is an apocalyptic number.

667871811 is a deficient number, since it is larger than the sum of its proper divisors (333726501).

667871811 is a wasteful number, since it uses less digits than its factorization.

667871811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32352 (or 32343 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 667871811 is about 25843.2159569973. The cubic root of 667871811 is about 874.1065431367.

The spelling of 667871811 in words is "six hundred sixty-seven million, eight hundred seventy-one thousand, eight hundred eleven".