66223784 has 72 divisors (see below), whose sum is σ = 143508330. Its totient is φ = 28607040.

The previous prime is 66223771. The next prime is 66223811. The reversal of 66223784 is 48732266.

It can be written as a sum of positive squares in only one way, i.e., 43850884 + 22372900 = 6622^2 + 4730^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1540067 + ... + 1540109.

Almost surely, 2^66223784 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66223784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71754165).

66223784 is an abundant number, since it is smaller than the sum of its proper divisors (77284546).

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

66223784 is a wasteful number, since it uses less digits than its factorization.

66223784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 93 counting only the distinct ones).

The product of its digits is 96768, while the sum is 38.

The square root of 66223784 is about 8137.7997026223. The cubic root of 66223784 is about 404.5802367312.

The spelling of 66223784 in words is "sixty-six million, two hundred twenty-three thousand, seven hundred eighty-four".