66724121 has 8 divisors (see below), whose sum is σ = 69548544. Its totient is φ = 63941760.

The previous prime is 66724109. The next prime is 66724123. The reversal of 66724121 is 12142766.

66724121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66724121 - 2¹⁴ = 66707737 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66724123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7256 + ... + 13641.

It is an arithmetic number, because the mean of its divisors is an integer number (8693568).

Almost surely, 2^66724121 is an apocalyptic number.

It is an amenable number.

66724121 is a deficient number, since it is larger than the sum of its proper divisors (2824423).

66724121 is a wasteful number, since it uses less digits than its factorization.

66724121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21031.

The product of its digits is 4032, while the sum is 29.

The square root of 66724121 is about 8168.4833965676. The cubic root of 66724121 is about 405.5965825456.

Adding to 66724121 its reverse (12142766), we get a palindrome (78866887).

The spelling of 66724121 in words is "sixty-six million, seven hundred twenty-four thousand, one hundred twenty-one".