66233509 has 2 divisors, whose sum is σ = 66233510. Its totient is φ = 66233508.

The previous prime is 66233507. The next prime is 66233549. The reversal of 66233509 is 90533266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63520900 + 2712609 = 7970^2 + 1647^2 .

It is a cyclic number.

It is not a de Polignac number, because 66233509 - 2¹ = 66233507 is a prime.

Together with 66233507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66233507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33116754 + 33116755.

It is an arithmetic number, because the mean of its divisors is an integer number (33116755).

Almost surely, 2^66233509 is an apocalyptic number.

It is an amenable number.

66233509 is a deficient number, since it is larger than the sum of its proper divisors (1).

66233509 is an equidigital number, since it uses as much as digits as its factorization.

66233509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 34.

The square root of 66233509 is about 8138.3972009235. The cubic root of 66233509 is about 404.6000400404.

The spelling of 66233509 in words is "sixty-six million, two hundred thirty-three thousand, five hundred nine".