66739289 has 2 divisors, whose sum is σ = 66739290. Its totient is φ = 66739288.

The previous prime is 66739271. The next prime is 66739291. The reversal of 66739289 is 98293766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51955264 + 14784025 = 7208^2 + 3845^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66739289 is a prime.

Together with 66739291, 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 (66739259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33369644 + 33369645.

It is an arithmetic number, because the mean of its divisors is an integer number (33369645).

Almost surely, 2^66739289 is an apocalyptic number.

It is an amenable number.

66739289 is a deficient number, since it is larger than the sum of its proper divisors (1).

66739289 is an equidigital number, since it uses as much as digits as its factorization.

66739289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 50.

The square root of 66739289 is about 8169.4117903311. The cubic root of 66739289 is about 405.6273141749.

The spelling of 66739289 in words is "sixty-six million, seven hundred thirty-nine thousand, two hundred eighty-nine".