66781168 has 20 divisors (see below), whose sum is σ = 137000160. Its totient is φ = 31426304.

The previous prime is 66781159. The next prime is 66781177. The reversal of 66781168 is 86118766.

It is an interprime number because it is at equal distance from previous prime (66781159) and next prime (66781177).

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122488 + ... + 123031.

It is an arithmetic number, because the mean of its divisors is an integer number (6850008).

Almost surely, 2^66781168 is an apocalyptic number.

66781168 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

66781168 is an abundant number, since it is smaller than the sum of its proper divisors (70218992).

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

66781168 is a wasteful number, since it uses less digits than its factorization.

66781168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245544 (or 245538 counting only the distinct ones).

The product of its digits is 96768, while the sum is 43.

The square root of 66781168 is about 8171.9745471948. The cubic root of 66781168 is about 405.7121403425.

The spelling of 66781168 in words is "sixty-six million, seven hundred eighty-one thousand, one hundred sixty-eight".