66081601 has 8 divisors (see below), whose sum is σ = 73651680. Its totient is φ = 58920768.

The previous prime is 66081581. The next prime is 66081611. The reversal of 66081601 is 10618066.

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 66081601 - 2⁵ = 66081569 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66081601.

It is not an unprimeable number, because it can be changed into a prime (66081611) 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, 101971 + ... + 102616.

It is an arithmetic number, because the mean of its divisors is an integer number (9206460).

Almost surely, 2^66081601 is an apocalyptic number.

It is an amenable number.

66081601 is a deficient number, since it is larger than the sum of its proper divisors (7570079).

66081601 is a wasteful number, since it uses less digits than its factorization.

66081601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204623.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 66081601 is about 8129.0590476389. The cubic root of 66081601 is about 404.2904835843.

Adding to 66081601 its reverse (10618066), we get a palindrome (76699667).

The spelling of 66081601 in words is "sixty-six million, eighty-one thousand, six hundred one".