66338749 has 4 divisors (see below), whose sum is σ = 67178560. Its totient is φ = 65498940.

The previous prime is 66338717. The next prime is 66338771. The reversal of 66338749 is 94783366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 94783366 = 2 ⋅47391683.

It is a cyclic number.

It is not a de Polignac number, because 66338749 - 2⁵ = 66338717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66338699 and 66338708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66338249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 419787 + ... + 419944.

It is an arithmetic number, because the mean of its divisors is an integer number (16794640).

Almost surely, 2^66338749 is an apocalyptic number.

It is an amenable number.

66338749 is a deficient number, since it is larger than the sum of its proper divisors (839811).

66338749 is an equidigital number, since it uses as much as digits as its factorization.

66338749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839810.

The product of its digits is 653184, while the sum is 46.

The square root of 66338749 is about 8144.8602811835. The cubic root of 66338749 is about 404.8142195223.

The spelling of 66338749 in words is "sixty-six million, three hundred thirty-eight thousand, seven hundred forty-nine".