66243321 has 9 divisors (see below), whose sum is σ = 95720079. Its totient is φ = 44145936.

The previous prime is 66243313. The next prime is 66243343. The reversal of 66243321 is 12334266.

The square root of 66243321 is 8139.

It is a perfect power (a square), and thus also a powerful number.

66243321 is a `hidden beast` number, since 6 + 624 + 3 + 32 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 65367225 + 876096 = 8085^2 + 936^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 66243321 - 2³ = 66243313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66243421) 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 8 ways as a sum of consecutive naturals, for example, 23061 + ... + 25773.

Almost surely, 2^66243321 is an apocalyptic number.

66243321 is the 8139-th square number.

66243321 is the 4070-th centered octagonal number.

It is an amenable number.

66243321 is a deficient number, since it is larger than the sum of its proper divisors (29476758).

66243321 is an frugal number, since it uses more digits than its factorization.

66243321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5432 (or 2716 counting only the distinct ones).

The product of its digits is 5184, while the sum is 27.

The cubic root of 66243321 is about 404.6200185459.

Multiplying 66243321 by its product of digits (5184), we get a square (343405376064 = 586008²).

Adding to 66243321 its reverse (12334266), we get a palindrome (78577587).

It can be divided in two parts, 66243 and 321, that added together give a square (66564 = 258²).

The spelling of 66243321 in words is "sixty-six million, two hundred forty-three thousand, three hundred twenty-one".