66280805 has 16 divisors (see below), whose sum is σ = 84294000. Its totient is φ = 49943040.

The previous prime is 66280783. The next prime is 66280859. The reversal of 66280805 is 50808266.

It can be written as a sum of positive squares in 8 ways, for example, as 12096484 + 54184321 = 3478^2 + 7361^2 .

It is not a de Polignac number, because 66280805 - 2¹² = 66276709 is a prime.

It is a super-2 number, since 2×66280805² = 8786290222896050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 371 + ... + 11519.

It is an arithmetic number, because the mean of its divisors is an integer number (5268375).

Almost surely, 2^66280805 is an apocalyptic number.

It is an amenable number.

66280805 is a deficient number, since it is larger than the sum of its proper divisors (18013195).

66280805 is a wasteful number, since it uses less digits than its factorization.

66280805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11224.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 66280805 is about 8141.3024142332. The cubic root of 66280805 is about 404.6963226760.

The spelling of 66280805 in words is "sixty-six million, two hundred eighty thousand, eight hundred five".