66440406 has 8 divisors (see below), whose sum is σ = 132880824. Its totient is φ = 22146800.

The previous prime is 66440401. The next prime is 66440447. The reversal of 66440406 is 60404466.

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

66440406 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66440401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5536695 + ... + 5536706.

It is an arithmetic number, because the mean of its divisors is an integer number (16610103).

Almost surely, 2^66440406 is an apocalyptic number.

66440406 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66440406 is a wasteful number, since it uses less digits than its factorization.

66440406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11073406.

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 66440406 is about 8151.0984535828. The cubic root of 66440406 is about 405.0208920788.

The spelling of 66440406 in words is "sixty-six million, four hundred forty thousand, four hundred six".