66072784 has 20 divisors (see below), whose sum is σ = 128165284. Its totient is φ = 32997888.

The previous prime is 66072779. The next prime is 66072791. The reversal of 66072784 is 48727066.

It can be written as a sum of positive squares in 2 ways, for example, as 4293184 + 61779600 = 2072^2 + 7860^2 .

It is a super-2 number, since 2×66072784² = 8731225571021312, 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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16024 + ... + 19720.

Almost surely, 2^66072784 is an apocalyptic number.

It is an amenable number.

66072784 is a deficient number, since it is larger than the sum of its proper divisors (62092500).

66072784 is a wasteful number, since it uses less digits than its factorization.

66072784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4822 (or 4816 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 40.

The square root of 66072784 is about 8128.5167158591. The cubic root of 66072784 is about 404.2725018380.

The spelling of 66072784 in words is "sixty-six million, seventy-two thousand, seven hundred eighty-four".