66778168 has 8 divisors (see below), whose sum is σ = 125209080. Its totient is φ = 33389080.

The previous prime is 66778157. The next prime is 66778171. The reversal of 66778168 is 86187766.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4173628 + ... + 4173643.

It is an arithmetic number, because the mean of its divisors is an integer number (15651135).

Almost surely, 2^66778168 is an apocalyptic number.

It is an amenable number.

66778168 is a deficient number, since it is larger than the sum of its proper divisors (58430912).

66778168 is a wasteful number, since it uses less digits than its factorization.

66778168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8347277 (or 8347273 counting only the distinct ones).

The product of its digits is 677376, while the sum is 49.

The square root of 66778168 is about 8171.7909909640. The cubic root of 66778168 is about 405.7060650038.

The spelling of 66778168 in words is "sixty-six million, seven hundred seventy-eight thousand, one hundred sixty-eight".