66388579 has 4 divisors (see below), whose sum is σ = 66416776. Its totient is φ = 66360384.

The previous prime is 66388561. The next prime is 66388657. The reversal of 66388579 is 97588366.

66388579 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97588366 = 2 ⋅48794183.

It is a cyclic number.

It is not a de Polignac number, because 66388579 - 2¹³ = 66380387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66388079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10209 + ... + 15394.

It is an arithmetic number, because the mean of its divisors is an integer number (16604194).

Almost surely, 2^66388579 is an apocalyptic number.

66388579 is a deficient number, since it is larger than the sum of its proper divisors (28197).

66388579 is a wasteful number, since it uses less digits than its factorization.

66388579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28196.

The product of its digits is 2177280, while the sum is 52.

The square root of 66388579 is about 8147.9186912978. The cubic root of 66388579 is about 404.9155521738.

The spelling of 66388579 in words is "sixty-six million, three hundred eighty-eight thousand, five hundred seventy-nine".