66665442 has 8 divisors (see below), whose sum is σ = 133330896. Its totient is φ = 22221812.

The previous prime is 66665441. The next prime is 66665447. The reversal of 66665442 is 24456666.

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

66665442 is an admirable number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66665442.

It is not an unprimeable number, because it can be changed into a prime (66665441) 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, 5555448 + ... + 5555459.

It is an arithmetic number, because the mean of its divisors is an integer number (16666362).

Almost surely, 2^66665442 is an apocalyptic number.

66665442 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.

66665442 is a wasteful number, since it uses less digits than its factorization.

66665442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11110912.

The product of its digits is 207360, while the sum is 39.

The square root of 66665442 is about 8164.8908137219. The cubic root of 66665442 is about 405.4776501330.

The spelling of 66665442 in words is "sixty-six million, six hundred sixty-five thousand, four hundred forty-two".