666788888971 has 2 divisors, whose sum is σ = 666788888972. Its totient is φ = 666788888970.

The previous prime is 666788888897. The next prime is 666788888999. The reversal of 666788888971 is 179888887666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666788888971 - 2¹⁵ = 666788856203 is a prime.

It is not a weakly prime, because it can be changed into another prime (666788889971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333394444485 + 333394444486.

It is an arithmetic number, because the mean of its divisors is an integer number (333394444486).

Almost surely, 2^666788888971 is an apocalyptic number.

666788888971 is a deficient number, since it is larger than the sum of its proper divisors (1).

666788888971 is an equidigital number, since it uses as much as digits as its factorization.

666788888971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3121348608, while the sum is 82.

The spelling of 666788888971 in words is "six hundred sixty-six billion, seven hundred eighty-eight million, eight hundred eighty-eight thousand, nine hundred seventy-one".