66915089 has 2 divisors, whose sum is σ = 66915090. Its totient is φ = 66915088.

The previous prime is 66915061. The next prime is 66915091. The reversal of 66915089 is 98051966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46348864 + 20566225 = 6808^2 + 4535^2 .

It is a cyclic number.

It is not a de Polignac number, because 66915089 - 2¹² = 66910993 is a prime.

Together with 66915091, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66915059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33457544 + 33457545.

It is an arithmetic number, because the mean of its divisors is an integer number (33457545).

Almost surely, 2^66915089 is an apocalyptic number.

It is an amenable number.

66915089 is a deficient number, since it is larger than the sum of its proper divisors (1).

66915089 is an equidigital number, since it uses as much as digits as its factorization.

66915089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 66915089 is about 8180.1643626519. The cubic root of 66915089 is about 405.9831603424.

The spelling of 66915089 in words is "sixty-six million, nine hundred fifteen thousand, eighty-nine".