66680778 has 16 divisors (see below), whose sum is σ = 134258400. Its totient is φ = 22077456.

The previous prime is 66680767. The next prime is 66680813. The reversal of 66680778 is 87708666.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36400 + ... + 38187.

It is an arithmetic number, because the mean of its divisors is an integer number (8391150).

Almost surely, 2^66680778 is an apocalyptic number.

66680778 is an abundant number, since it is smaller than the sum of its proper divisors (67577622).

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

66680778 is a wasteful number, since it uses less digits than its factorization.

66680778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74741.

The product of its (nonzero) digits is 677376, while the sum is 48.

The square root of 66680778 is about 8165.8299027104. The cubic root of 66680778 is about 405.5087403465.

The spelling of 66680778 in words is "sixty-six million, six hundred eighty thousand, seven hundred seventy-eight".