66968978 has 16 divisors (see below), whose sum is σ = 101595264. Its totient is φ = 33106320.

The previous prime is 66968971. The next prime is 66968981. The reversal of 66968978 is 87986966.

It is not an unprimeable number, because it can be changed into a prime (66968971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84701 + ... + 85487.

It is an arithmetic number, because the mean of its divisors is an integer number (6349704).

Almost surely, 2^66968978 is an apocalyptic number.

66968978 is a deficient number, since it is larger than the sum of its proper divisors (34626286).

66968978 is a wasteful number, since it uses less digits than its factorization.

66968978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1217.

The product of its digits is 7838208, while the sum is 59.

The square root of 66968978 is about 8183.4575822204. The cubic root of 66968978 is about 406.0921151210.

The spelling of 66968978 in words is "sixty-six million, nine hundred sixty-eight thousand, nine hundred seventy-eight".