66042140721 has 8 divisors (see below), whose sum is σ = 88503174144. Its totient is φ = 43804600560.

The previous prime is 66042140711. The next prime is 66042140737. The reversal of 66042140721 is 12704124066.

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

It is not a de Polignac number, because 66042140721 - 2²¹ = 66040043569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66042140701) 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, 55872625 + ... + 55873806.

It is an arithmetic number, because the mean of its divisors is an integer number (11062896768).

Almost surely, 2^66042140721 is an apocalyptic number.

It is an amenable number.

66042140721 is a deficient number, since it is larger than the sum of its proper divisors (22461033423).

66042140721 is a wasteful number, since it uses less digits than its factorization.

66042140721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111746631.

The product of its (nonzero) digits is 16128, while the sum is 33.

Adding to 66042140721 its reverse (12704124066), we get a palindrome (78746264787).

The spelling of 66042140721 in words is "sixty-six billion, forty-two million, one hundred forty thousand, seven hundred twenty-one".