66701278 has 16 divisors (see below), whose sum is σ = 114457824. Its totient is φ = 28558080.

The previous prime is 66701273. The next prime is 66701279. The reversal of 66701278 is 87210766.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66701273) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 19126 + ... + 22342.

It is an arithmetic number, because the mean of its divisors is an integer number (7153614).

Almost surely, 2^66701278 is an apocalyptic number.

66701278 is a deficient number, since it is larger than the sum of its proper divisors (47756546).

66701278 is a wasteful number, since it uses less digits than its factorization.

66701278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4707.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 66701278 is about 8167.0850369027. The cubic root of 66701278 is about 405.5502919384.

The spelling of 66701278 in words is "sixty-six million, seven hundred one thousand, two hundred seventy-eight".