66888869 has 2 divisors, whose sum is σ = 66888870. Its totient is φ = 66888868.

The previous prime is 66888841. The next prime is 66888883. The reversal of 66888869 is 96888866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65011969 + 1876900 = 8063^2 + 1370^2 .

It is a cyclic number.

It is not a de Polignac number, because 66888869 - 2¹² = 66884773 is a prime.

It is a super-2 number, since 2×66888869² = 8948241592198322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66888889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33444434 + 33444435.

It is an arithmetic number, because the mean of its divisors is an integer number (33444435).

Almost surely, 2^66888869 is an apocalyptic number.

It is an amenable number.

66888869 is a deficient number, since it is larger than the sum of its proper divisors (1).

66888869 is an equidigital number, since it uses as much as digits as its factorization.

66888869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7962624, while the sum is 59.

The square root of 66888869 is about 8178.5615483409. The cubic root of 66888869 is about 405.9301266182.

The spelling of 66888869 in words is "sixty-six million, eight hundred eighty-eight thousand, eight hundred sixty-nine".