66704569 has 4 divisors (see below), whose sum is σ = 66793444. Its totient is φ = 66615696.

The previous prime is 66704557. The next prime is 66704579. The reversal of 66704569 is 96540766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52925625 + 13778944 = 7275^2 + 3712^2 .

It is a cyclic number.

It is not a de Polignac number, because 66704569 - 2⁷ = 66704441 is a prime.

It is a super-2 number, since 2×66704569² = 8898999050951522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66704579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43302 + ... + 44815.

It is an arithmetic number, because the mean of its divisors is an integer number (16698361).

Almost surely, 2^66704569 is an apocalyptic number.

It is an amenable number.

66704569 is a deficient number, since it is larger than the sum of its proper divisors (88875).

66704569 is an equidigital number, since it uses as much as digits as its factorization.

66704569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88874.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 66704569 is about 8167.2865138919. The cubic root of 66704569 is about 405.5569616960.

The spelling of 66704569 in words is "sixty-six million, seven hundred four thousand, five hundred sixty-nine".