66657678 has 8 divisors (see below), whose sum is σ = 133315368. Its totient is φ = 22219224.

The previous prime is 66657673. The next prime is 66657713. The reversal of 66657678 is 87675666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

66657678 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 66657678.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66657673) 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, 5554801 + ... + 5554812.

It is an arithmetic number, because the mean of its divisors is an integer number (16664421).

Almost surely, 2^66657678 is an apocalyptic number.

66657678 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66657678 is a wasteful number, since it uses less digits than its factorization.

66657678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11109618.

The product of its digits is 2540160, while the sum is 51.

The square root of 66657678 is about 8164.4153495520. The cubic root of 66657678 is about 405.4619085904.

The spelling of 66657678 in words is "sixty-six million, six hundred fifty-seven thousand, six hundred seventy-eight".