66716121 has 8 divisors (see below), whose sum is σ = 90282784. Its totient is φ = 43813440.

The previous prime is 66716119. The next prime is 66716129. The reversal of 66716121 is 12161766.

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

It is not a de Polignac number, because 66716121 - 2¹ = 66716119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66716129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165760 + ... + 166161.

It is an arithmetic number, because the mean of its divisors is an integer number (11285348).

Almost surely, 2^66716121 is an apocalyptic number.

It is an amenable number.

66716121 is a deficient number, since it is larger than the sum of its proper divisors (23566663).

66716121 is a wasteful number, since it uses less digits than its factorization.

66716121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331991.

The product of its digits is 3024, while the sum is 30.

The square root of 66716121 is about 8167.9936949045. The cubic root of 66716121 is about 405.5803720044.

Adding to 66716121 its reverse (12161766), we get a palindrome (78877887).

The spelling of 66716121 in words is "sixty-six million, seven hundred sixteen thousand, one hundred twenty-one".