665263526491 has 2 divisors, whose sum is σ = 665263526492. Its totient is φ = 665263526490.

The previous prime is 665263526483. The next prime is 665263526503. The reversal of 665263526491 is 194625362566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665263526491 - 2³ = 665263526483 is a prime.

It is not a weakly prime, because it can be changed into another prime (665263526401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332631763245 + 332631763246.

It is an arithmetic number, because the mean of its divisors is an integer number (332631763246).

Almost surely, 2^665263526491 is an apocalyptic number.

665263526491 is a deficient number, since it is larger than the sum of its proper divisors (1).

665263526491 is an equidigital number, since it uses as much as digits as its factorization.

665263526491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13996800, while the sum is 55.

The spelling of 665263526491 in words is "six hundred sixty-five billion, two hundred sixty-three million, five hundred twenty-six thousand, four hundred ninety-one".