665259851 has 2 divisors, whose sum is σ = 665259852. Its totient is φ = 665259850.

The previous prime is 665259823. The next prime is 665259871. The reversal of 665259851 is 158952566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665259851 - 2²² = 661065547 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 665259796 and 665259805.

It is not a weakly prime, because it can be changed into another prime (665259811) 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 as a sum of consecutive naturals, namely, 332629925 + 332629926.

It is an arithmetic number, because the mean of its divisors is an integer number (332629926).

Almost surely, 2^665259851 is an apocalyptic number.

665259851 is a deficient number, since it is larger than the sum of its proper divisors (1).

665259851 is an equidigital number, since it uses as much as digits as its factorization.

665259851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648000, while the sum is 47.

The square root of 665259851 is about 25792.6317191558. The cubic root of 665259851 is about 872.9655486545.

The spelling of 665259851 in words is "six hundred sixty-five million, two hundred fifty-nine thousand, eight hundred fifty-one".