66718916 has 18 divisors (see below), whose sum is σ = 128338350. Its totient is φ = 30326560.

The previous prime is 66718903. The next prime is 66718919. The reversal of 66718916 is 61981766.

66718916 = T₁₁ + T₁₂ + ... + T₇₃₆.

66718916 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 64480900 + 2238016 = 8030^2 + 1496^2 .

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (66718919) by changing a digit.

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 in 5 ways as a sum of consecutive naturals, for example, 68441 + ... + 69408.

Almost surely, 2^66718916 is an apocalyptic number.

It is an amenable number.

66718916 is a deficient number, since it is larger than the sum of its proper divisors (61619434).

66718916 is a wasteful number, since it uses less digits than its factorization.

66718916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137875 (or 137862 counting only the distinct ones).

The product of its digits is 108864, while the sum is 44.

The square root of 66718916 is about 8168.1647877599. The cubic root of 66718916 is about 405.5860357095.

The spelling of 66718916 in words is "sixty-six million, seven hundred eighteen thousand, nine hundred sixteen".