66724279 has 4 divisors (see below), whose sum is σ = 67474080. Its totient is φ = 65974480.

The previous prime is 66724277. The next prime is 66724289. The reversal of 66724279 is 97242766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97242766 = 2 ⋅48621383.

It is a cyclic number.

It is not a de Polignac number, because 66724279 - 2¹ = 66724277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66724271) 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, 374767 + ... + 374944.

It is an arithmetic number, because the mean of its divisors is an integer number (16868520).

Almost surely, 2^66724279 is an apocalyptic number.

66724279 is a deficient number, since it is larger than the sum of its proper divisors (749801).

66724279 is an equidigital number, since it uses as much as digits as its factorization.

66724279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 749800.

The product of its digits is 254016, while the sum is 43.

The square root of 66724279 is about 8168.4930678798. The cubic root of 66724279 is about 405.5969026907.

The spelling of 66724279 in words is "sixty-six million, seven hundred twenty-four thousand, two hundred seventy-nine".