66427778 has 8 divisors (see below), whose sum is σ = 99676668. Its totient is φ = 33202224.

The previous prime is 66427771. The next prime is 66427787. The reversal of 66427778 is 87772466.

It can be written as a sum of positive squares in 2 ways, for example, as 62047129 + 4380649 = 7877^2 + 2093^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66427771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6500 + ... + 13232.

Almost surely, 2^66427778 is an apocalyptic number.

66427778 is a deficient number, since it is larger than the sum of its proper divisors (33248890).

66427778 is a wasteful number, since it uses less digits than its factorization.

66427778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11668.

The product of its digits is 790272, while the sum is 47.

The square root of 66427778 is about 8150.3237972488. The cubic root of 66427778 is about 404.9952303457.

The spelling of 66427778 in words is "sixty-six million, four hundred twenty-seven thousand, seven hundred seventy-eight".