66678393 has 16 divisors (see below), whose sum is σ = 89907840. Its totient is φ = 43954176.

The previous prime is 66678379. The next prime is 66678421. The reversal of 66678393 is 39387666.

It is a happy number.

It is not a de Polignac number, because 66678393 - 2⁸ = 66678137 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66678323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 151668 + ... + 152106.

It is an arithmetic number, because the mean of its divisors is an integer number (5619240).

Almost surely, 2^66678393 is an apocalyptic number.

It is an amenable number.

66678393 is a deficient number, since it is larger than the sum of its proper divisors (23229447).

66678393 is a wasteful number, since it uses less digits than its factorization.

66678393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 896.

The product of its digits is 979776, while the sum is 48.

The square root of 66678393 is about 8165.6838660335. The cubic root of 66678393 is about 405.5039056205.

The spelling of 66678393 in words is "sixty-six million, six hundred seventy-eight thousand, three hundred ninety-three".