66752009 has 2 divisors, whose sum is σ = 66752010. Its totient is φ = 66752008.

The previous prime is 66751981. The next prime is 66752029. The reversal of 66752009 is 90025766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36336784 + 30415225 = 6028^2 + 5515^2 .

It is a cyclic number.

It is not a de Polignac number, because 66752009 - 2⁸ = 66751753 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66752009.

It is not a weakly prime, because it can be changed into another prime (66752029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33376004 + 33376005.

It is an arithmetic number, because the mean of its divisors is an integer number (33376005).

Almost surely, 2^66752009 is an apocalyptic number.

It is an amenable number.

66752009 is a deficient number, since it is larger than the sum of its proper divisors (1).

66752009 is an equidigital number, since it uses as much as digits as its factorization.

66752009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 66752009 is about 8170.1902670623. The cubic root of 66752009 is about 405.6530823631.

The spelling of 66752009 in words is "sixty-six million, seven hundred fifty-two thousand, nine".