666312811 has 2 divisors, whose sum is σ = 666312812. Its totient is φ = 666312810.

The previous prime is 666312809. The next prime is 666312839. The reversal of 666312811 is 118213666.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666312811 - 2¹ = 666312809 is a prime.

Together with 666312809, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (666312011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333156405 + 333156406.

It is an arithmetic number, because the mean of its divisors is an integer number (333156406).

Almost surely, 2^666312811 is an apocalyptic number.

666312811 is a deficient number, since it is larger than the sum of its proper divisors (1).

666312811 is an equidigital number, since it uses as much as digits as its factorization.

666312811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 666312811 is about 25813.0356796716. The cubic root of 666312811 is about 873.4258766833.

The spelling of 666312811 in words is "six hundred sixty-six million, three hundred twelve thousand, eight hundred eleven".