66666669977 has 2 divisors, whose sum is σ = 66666669978. Its totient is φ = 66666669976.

The previous prime is 66666669917. The next prime is 66666669983. The reversal of 66666669977 is 77996666666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47047345216 + 19619324761 = 216904^2 + 140069^2 .

It is a cyclic number.

It is not a de Polignac number, because 66666669977 - 2⁸ = 66666669721 is a prime.

It is a zygodrome in base 10.

It is not a weakly prime, because it can be changed into another prime (66666669907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333334988 + 33333334989.

It is an arithmetic number, because the mean of its divisors is an integer number (33333334989).

Almost surely, 2^66666669977 is an apocalyptic number.

It is an amenable number.

66666669977 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666669977 is an equidigital number, since it uses as much as digits as its factorization.

66666669977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1111065984, while the sum is 74.

The spelling of 66666669977 in words is "sixty-six billion, six hundred sixty-six million, six hundred sixty-nine thousand, nine hundred seventy-seven".