66565139 has 2 divisors, whose sum is σ = 66565140. Its totient is φ = 66565138.

The previous prime is 66565129. The next prime is 66565141. The reversal of 66565139 is 93156566.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66565139 is a prime.

Together with 66565141, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66565096 and 66565105.

It is not a weakly prime, because it can be changed into another prime (66565129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33282569 + 33282570.

It is an arithmetic number, because the mean of its divisors is an integer number (33282570).

Almost surely, 2^66565139 is an apocalyptic number.

66565139 is a deficient number, since it is larger than the sum of its proper divisors (1).

66565139 is an equidigital number, since it uses as much as digits as its factorization.

66565139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145800, while the sum is 41.

The square root of 66565139 is about 8158.7461659253. The cubic root of 66565139 is about 405.2741911999.

The spelling of 66565139 in words is "sixty-six million, five hundred sixty-five thousand, one hundred thirty-nine".