66678329 has 4 divisors (see below), whose sum is σ = 68480484. Its totient is φ = 64876176.

The previous prime is 66678323. The next prime is 66678347. The reversal of 66678329 is 92387666.

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 25050025 + 41628304 = 5005^2 + 6452^2 .

It is a cyclic number.

It is not a de Polignac number, because 66678329 - 2¹² = 66674233 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66678323) 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, 901022 + ... + 901095.

It is an arithmetic number, because the mean of its divisors is an integer number (17120121).

Almost surely, 2^66678329 is an apocalyptic number.

It is an amenable number.

66678329 is a deficient number, since it is larger than the sum of its proper divisors (1802155).

66678329 is a wasteful number, since it uses less digits than its factorization.

66678329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1802154.

The product of its digits is 653184, while the sum is 47.

The square root of 66678329 is about 8165.6799471936. The cubic root of 66678329 is about 405.5037758820.

The spelling of 66678329 in words is "sixty-six million, six hundred seventy-eight thousand, three hundred twenty-nine".