66976978 has 8 divisors (see below), whose sum is σ = 100636668. Its totient is φ = 33431424.

The previous prime is 66976961. The next prime is 66976981. The reversal of 66976978 is 87967966.

It can be written as a sum of positive squares in 2 ways, for example, as 65173329 + 1803649 = 8073^2 + 1343^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27051 + ... + 29422.

Almost surely, 2^66976978 is an apocalyptic number.

66976978 is a deficient number, since it is larger than the sum of its proper divisors (33659690).

66976978 is a wasteful number, since it uses less digits than its factorization.

66976978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57068.

The product of its digits is 6858432, while the sum is 58.

The square root of 66976978 is about 8183.9463585730. The cubic root of 66976978 is about 406.1082848345.

The spelling of 66976978 in words is "sixty-six million, nine hundred seventy-six thousand, nine hundred seventy-eight".