656665566679 has 2 divisors, whose sum is σ = 656665566680. Its totient is φ = 656665566678.

The previous prime is 656665566643. The next prime is 656665566719. The reversal of 656665566679 is 976665566656.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 656665566679 - 2²⁷ = 656531348951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656665563679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328332783339 + 328332783340.

It is an arithmetic number, because the mean of its divisors is an integer number (328332783340).

Almost surely, 2^656665566679 is an apocalyptic number.

656665566679 is a deficient number, since it is larger than the sum of its proper divisors (1).

656665566679 is an equidigital number, since it uses as much as digits as its factorization.

656665566679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2204496000, while the sum is 73.

The spelling of 656665566679 in words is "six hundred fifty-six billion, six hundred sixty-five million, five hundred sixty-six thousand, six hundred seventy-nine".