66440001 has 8 divisors (see below), whose sum is σ = 89800480. Its totient is φ = 43686432.

The previous prime is 66439981. The next prime is 66440009. The reversal of 66440001 is 10004466.

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

It is not a de Polignac number, because 66440001 - 2⁷ = 66439873 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66440001.

It is not an unprimeable number, because it can be changed into a prime (66440009) 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, 151471 + ... + 151908.

It is an arithmetic number, because the mean of its divisors is an integer number (11225060).

Almost surely, 2^66440001 is an apocalyptic number.

It is an amenable number.

66440001 is a deficient number, since it is larger than the sum of its proper divisors (23360479).

66440001 is a wasteful number, since it uses less digits than its factorization.

66440001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303455.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 66440001 is about 8151.0736102675. The cubic root of 66440001 is about 405.0200691168.

Adding to 66440001 its reverse (10004466), we get a palindrome (76444467).

The spelling of 66440001 in words is "sixty-six million, four hundred forty thousand, one".