666197827 has 2 divisors, whose sum is σ = 666197828. Its totient is φ = 666197826.

The previous prime is 666197813. The next prime is 666197837. The reversal of 666197827 is 728791666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666197827 - 2⁷ = 666197699 is a prime.

It is not a weakly prime, because it can be changed into another prime (666197837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333098913 + 333098914.

It is an arithmetic number, because the mean of its divisors is an integer number (333098914).

Almost surely, 2^666197827 is an apocalyptic number.

666197827 is a deficient number, since it is larger than the sum of its proper divisors (1).

666197827 is an equidigital number, since it uses as much as digits as its factorization.

666197827 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 52.

The square root of 666197827 is about 25810.8083368189. The cubic root of 666197827 is about 873.3756321250.

The spelling of 666197827 in words is "six hundred sixty-six million, one hundred ninety-seven thousand, eight hundred twenty-seven".