66390851 has 2 divisors, whose sum is σ = 66390852. Its totient is φ = 66390850.

The previous prime is 66390833. The next prime is 66390853. The reversal of 66390851 is 15809366.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66390851 is a prime.

It is a Sophie Germain prime.

Together with 66390853, 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 (66390853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33195425 + 33195426.

It is an arithmetic number, because the mean of its divisors is an integer number (33195426).

Almost surely, 2^66390851 is an apocalyptic number.

66390851 is a deficient number, since it is larger than the sum of its proper divisors (1).

66390851 is an equidigital number, since it uses as much as digits as its factorization.

66390851 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 66390851 is about 8148.0581122130. The cubic root of 66390851 is about 404.9201712295.

The spelling of 66390851 in words is "sixty-six million, three hundred ninety thousand, eight hundred fifty-one".