66378679 has 4 divisors (see below), whose sum is σ = 66444840. Its totient is φ = 66312520.

The previous prime is 66378661. The next prime is 66378691. The reversal of 66378679 is 97687366.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66378679 - 2⁷ = 66378551 is a prime.

It is a super-2 number, since 2×66378679² = 8812258051570082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66378079) 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, 31552 + ... + 33589.

It is an arithmetic number, because the mean of its divisors is an integer number (16611210).

Almost surely, 2^66378679 is an apocalyptic number.

66378679 is a deficient number, since it is larger than the sum of its proper divisors (66161).

66378679 is a wasteful number, since it uses less digits than its factorization.

66378679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66160.

The product of its digits is 2286144, while the sum is 52.

The square root of 66378679 is about 8147.3111515395. The cubic root of 66378679 is about 404.8954238962.

The spelling of 66378679 in words is "sixty-six million, three hundred seventy-eight thousand, six hundred seventy-nine".