66398679 has 6 divisors (see below), whose sum is σ = 95909216. Its totient is φ = 44265780.

The previous prime is 66398671. The next prime is 66398681. The reversal of 66398679 is 97689366.

It is a happy number.

It is not a de Polignac number, because 66398679 - 2³ = 66398671 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 (66398671) 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 5 ways as a sum of consecutive naturals, for example, 3688807 + ... + 3688824.

Almost surely, 2^66398679 is an apocalyptic number.

66398679 is a deficient number, since it is larger than the sum of its proper divisors (29510537).

66398679 is a wasteful number, since it uses less digits than its factorization.

66398679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7377637 (or 7377634 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 54.

The square root of 66398679 is about 8148.5384579077. The cubic root of 66398679 is about 404.9360850213.

The spelling of 66398679 in words is "sixty-six million, three hundred ninety-eight thousand, six hundred seventy-nine".