665660478737 has 2 divisors, whose sum is σ = 665660478738. Its totient is φ = 665660478736.

The previous prime is 665660478727. The next prime is 665660478803. The reversal of 665660478737 is 737874066566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 400516842496 + 265143636241 = 632864^2 + 514921^2 .

It is a cyclic number.

It is not a de Polignac number, because 665660478737 - 2⁸ = 665660478481 is a prime.

It is not a weakly prime, because it can be changed into another prime (665660478727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332830239368 + 332830239369.

It is an arithmetic number, because the mean of its divisors is an integer number (332830239369).

Almost surely, 2^665660478737 is an apocalyptic number.

It is an amenable number.

665660478737 is a deficient number, since it is larger than the sum of its proper divisors (1).

665660478737 is an equidigital number, since it uses as much as digits as its factorization.

665660478737 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 213373440, while the sum is 65.

The spelling of 665660478737 in words is "six hundred sixty-five billion, six hundred sixty million, four hundred seventy-eight thousand, seven hundred thirty-seven".