66921089 has 2 divisors, whose sum is σ = 66921090. Its totient is φ = 66921088.

The previous prime is 66921083. The next prime is 66921103. The reversal of 66921089 is 98012966.

66921089 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42250000 + 24671089 = 6500^2 + 4967^2 .

It is a cyclic number.

It is not a de Polignac number, because 66921089 - 2⁴ = 66921073 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66921083) 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, 33460544 + 33460545.

It is an arithmetic number, because the mean of its divisors is an integer number (33460545).

Almost surely, 2^66921089 is an apocalyptic number.

It is an amenable number.

66921089 is a deficient number, since it is larger than the sum of its proper divisors (1).

66921089 is an equidigital number, since it uses as much as digits as its factorization.

66921089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 66921089 is about 8180.5310952285. The cubic root of 66921089 is about 405.9952942582.

The spelling of 66921089 in words is "sixty-six million, nine hundred twenty-one thousand, eighty-nine".