666061665523 has 2 divisors, whose sum is σ = 666061665524. Its totient is φ = 666061665522.

The previous prime is 666061665463. The next prime is 666061665547. The reversal of 666061665523 is 325566160666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666061665523 - 2⁹ = 666061665011 is a prime.

It is not a weakly prime, because it can be changed into another prime (666061665023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333030832761 + 333030832762.

It is an arithmetic number, because the mean of its divisors is an integer number (333030832762).

Almost surely, 2^666061665523 is an apocalyptic number.

666061665523 is a deficient number, since it is larger than the sum of its proper divisors (1).

666061665523 is an equidigital number, since it uses as much as digits as its factorization.

666061665523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6998400, while the sum is 52.

The spelling of 666061665523 in words is "six hundred sixty-six billion, sixty-one million, six hundred sixty-five thousand, five hundred twenty-three".