66982978 has 4 divisors (see below), whose sum is σ = 100474470. Its totient is φ = 33491488.

The previous prime is 66982957. The next prime is 66982991. The reversal of 66982978 is 87928966.

66982978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87928966 = 2 ⋅43964483.

It can be written as a sum of positive squares in only one way, i.e., 36036009 + 30946969 = 6003^2 + 5563^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16745743 + ... + 16745746.

Almost surely, 2^66982978 is an apocalyptic number.

66982978 is a deficient number, since it is larger than the sum of its proper divisors (33491492).

66982978 is a wasteful number, since it uses less digits than its factorization.

66982978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33491491.

The product of its digits is 2612736, while the sum is 55.

The square root of 66982978 is about 8184.3129216813. The cubic root of 66982978 is about 406.1204112747.

The spelling of 66982978 in words is "sixty-six million, nine hundred eighty-two thousand, nine hundred seventy-eight".