66978687966 has 8 divisors (see below), whose sum is σ = 133957375944. Its totient is φ = 22326229320.

The previous prime is 66978687953. The next prime is 66978687967.

66978687966 is nontrivially palindromic in base 10.

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

66978687966 is an admirable number.

It is a super-2 number, since 2×66978687966² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66978687891 and 66978687900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66978687967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5581557325 + ... + 5581557336.

It is an arithmetic number, because the mean of its divisors is an integer number (16744671993).

Almost surely, 2^66978687966 is an apocalyptic number.

66978687966 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.

66978687966 is a wasteful number, since it uses less digits than its factorization.

66978687966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11163114666.

The product of its digits is 1975228416, while the sum is 78.

The spelling of 66978687966 in words is "sixty-six billion, nine hundred seventy-eight million, six hundred eighty-seven thousand, nine hundred sixty-six".