66123389 has 2 divisors, whose sum is σ = 66123390. Its totient is φ = 66123388.

The previous prime is 66123377. The next prime is 66123443. The reversal of 66123389 is 98332166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65205625 + 917764 = 8075^2 + 958^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66123389 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66123349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33061694 + 33061695.

It is an arithmetic number, because the mean of its divisors is an integer number (33061695).

Almost surely, 2^66123389 is an apocalyptic number.

It is an amenable number.

66123389 is a deficient number, since it is larger than the sum of its proper divisors (1).

66123389 is an equidigital number, since it uses as much as digits as its factorization.

66123389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 38.

The square root of 66123389 is about 8131.6289266051. The cubic root of 66123389 is about 404.3756859731.

It can be divided in two parts, 6612 and 3389, that added together give a palindrome (10001).

The spelling of 66123389 in words is "sixty-six million, one hundred twenty-three thousand, three hundred eighty-nine".