66509075 has 12 divisors (see below), whose sum is σ = 83231280. Its totient is φ = 52716960.

The previous prime is 66509039. The next prime is 66509087. The reversal of 66509075 is 57090566.

66509075 = 278² + 279² + ... + 604².

It is not a de Polignac number, because 66509075 - 2¹⁴ = 66492691 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9479 + ... + 14928.

It is an arithmetic number, because the mean of its divisors is an integer number (6935940).

Almost surely, 2^66509075 is an apocalyptic number.

66509075 is a deficient number, since it is larger than the sum of its proper divisors (16722205).

66509075 is a wasteful number, since it uses less digits than its factorization.

66509075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24526 (or 24521 counting only the distinct ones).

The product of its (nonzero) digits is 56700, while the sum is 38.

The square root of 66509075 is about 8155.3096201187. The cubic root of 66509075 is about 405.1603795034.

The spelling of 66509075 in words is "sixty-six million, five hundred nine thousand, seventy-five".