665434357391 has 2 divisors, whose sum is σ = 665434357392. Its totient is φ = 665434357390.

The previous prime is 665434357351. The next prime is 665434357411. The reversal of 665434357391 is 193753434566.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665434357391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665434357351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332717178695 + 332717178696.

It is an arithmetic number, because the mean of its divisors is an integer number (332717178696).

Almost surely, 2^665434357391 is an apocalyptic number.

665434357391 is a deficient number, since it is larger than the sum of its proper divisors (1).

665434357391 is an equidigital number, since it uses as much as digits as its factorization.

665434357391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24494400, while the sum is 56.

The spelling of 665434357391 in words is "six hundred sixty-five billion, four hundred thirty-four million, three hundred fifty-seven thousand, three hundred ninety-one".