665912851 has 2 divisors, whose sum is σ = 665912852. Its totient is φ = 665912850.

The previous prime is 665912843. The next prime is 665912887. The reversal of 665912851 is 158219566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665912851 - 2³ = 665912843 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665912798 and 665912807.

It is not a weakly prime, because it can be changed into another prime (665915851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332956425 + 332956426.

It is an arithmetic number, because the mean of its divisors is an integer number (332956426).

Almost surely, 2^665912851 is an apocalyptic number.

665912851 is a deficient number, since it is larger than the sum of its proper divisors (1).

665912851 is an equidigital number, since it uses as much as digits as its factorization.

665912851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 43.

The square root of 665912851 is about 25805.2872683100. The cubic root of 665912851 is about 873.2510812377.

The spelling of 665912851 in words is "six hundred sixty-five million, nine hundred twelve thousand, eight hundred fifty-one".