66980869 has 2 divisors, whose sum is σ = 66980870. Its totient is φ = 66980868.

The previous prime is 66980819. The next prime is 66980873. The reversal of 66980869 is 96808966.

66980869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50481025 + 16499844 = 7105^2 + 4062^2 .

It is a cyclic number.

It is not a de Polignac number, because 66980869 - 2¹³ = 66972677 is a prime.

It is a super-2 number, since 2×66980869² = 8972873623990322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66980819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33490434 + 33490435.

It is an arithmetic number, because the mean of its divisors is an integer number (33490435).

Almost surely, 2^66980869 is an apocalyptic number.

It is an amenable number.

66980869 is a deficient number, since it is larger than the sum of its proper divisors (1).

66980869 is an equidigital number, since it uses as much as digits as its factorization.

66980869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1119744, while the sum is 52.

The square root of 66980869 is about 8184.1840766200. The cubic root of 66980869 is about 406.1161489135.

The spelling of 66980869 in words is "sixty-six million, nine hundred eighty thousand, eight hundred sixty-nine".