66733872241 has 3 divisors (see below), whose sum is σ = 66734130571. Its totient is φ = 66733613912.

The previous prime is 66733872229. The next prime is 66733872269. The reversal of 66733872241 is 14227833766.

The square root of 66733872241 is 258329.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 44995318641 + 21738553600 = 212121^2 + 147440^2 .

It is not a de Polignac number, because 66733872241 - 2¹¹ = 66733870193 is a prime.

It is a super-2 number, since 2×66733872241² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66733872641) 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 2 ways as a sum of consecutive naturals, for example, 129165 + ... + 387493.

Almost surely, 2^66733872241 is an apocalyptic number.

66733872241 is the 258329-th square number.

66733872241 is the 129165-th centered octagonal number.

It is an amenable number.

66733872241 is a deficient number, since it is larger than the sum of its proper divisors (258330).

66733872241 is an frugal number, since it uses more digits than its factorization.

66733872241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516658 (or 258329 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 49.

Multiplying 66733872241 by its sum of digits (49), we get a square (3269959739809 = 1808303²).

The spelling of 66733872241 in words is "sixty-six billion, seven hundred thirty-three million, eight hundred seventy-two thousand, two hundred forty-one".