66556278 has 24 divisors (see below), whose sum is σ = 151795800. Its totient is φ = 21017664.

The previous prime is 66556271. The next prime is 66556279. The reversal of 66556278 is 87265566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66556271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 96963 + ... + 97646.

It is an arithmetic number, because the mean of its divisors is an integer number (6324825).

Almost surely, 2^66556278 is an apocalyptic number.

66556278 is an abundant number, since it is smaller than the sum of its proper divisors (85239522).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66556278 is a wasteful number, since it uses less digits than its factorization.

66556278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194636 (or 194633 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 66556278 is about 8158.2031109798. The cubic root of 66556278 is about 405.2562073422.

The spelling of 66556278 in words is "sixty-six million, five hundred fifty-six thousand, two hundred seventy-eight".