665717472811 has 2 divisors, whose sum is σ = 665717472812. Its totient is φ = 665717472810.

The previous prime is 665717472757. The next prime is 665717472821. The reversal of 665717472811 is 118274717566.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665717472811 - 2¹³ = 665717464619 is a prime.

It is not a weakly prime, because it can be changed into another prime (665717472821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332858736405 + 332858736406.

It is an arithmetic number, because the mean of its divisors is an integer number (332858736406).

Almost surely, 2^665717472811 is an apocalyptic number.

665717472811 is a deficient number, since it is larger than the sum of its proper divisors (1).

665717472811 is an equidigital number, since it uses as much as digits as its factorization.

665717472811 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3951360, while the sum is 55.

The spelling of 665717472811 in words is "six hundred sixty-five billion, seven hundred seventeen million, four hundred seventy-two thousand, eight hundred eleven".