66579647 has 4 divisors (see below), whose sum is σ = 66602760. Its totient is φ = 66556536.

The previous prime is 66579637. The next prime is 66579649. The reversal of 66579647 is 74697566.

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

It is a cyclic number.

It is not a de Polignac number, because 66579647 - 2¹⁰ = 66578623 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66579595 and 66579604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66579649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6497 + ... + 13242.

It is an arithmetic number, because the mean of its divisors is an integer number (16650690).

Almost surely, 2^66579647 is an apocalyptic number.

66579647 is a deficient number, since it is larger than the sum of its proper divisors (23113).

66579647 is a wasteful number, since it uses less digits than its factorization.

66579647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23112.

The product of its digits is 1905120, while the sum is 50.

The square root of 66579647 is about 8159.6352246899. The cubic root of 66579647 is about 405.3036324908.

The spelling of 66579647 in words is "sixty-six million, five hundred seventy-nine thousand, six hundred forty-seven".