66440193 has 16 divisors (see below), whose sum is σ = 89698560. Its totient is φ = 43741584.

The previous prime is 66440173. The next prime is 66440201. The reversal of 66440193 is 39104466.

66440193 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66440193 - 2¹⁷ = 66309121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66440113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117730 + ... + 118292.

It is an arithmetic number, because the mean of its divisors is an integer number (5606160).

Almost surely, 2^66440193 is an apocalyptic number.

It is an amenable number.

66440193 is a deficient number, since it is larger than the sum of its proper divisors (23258367).

66440193 is a wasteful number, since it uses less digits than its factorization.

66440193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 988.

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 66440193 is about 8151.0853878487. The cubic root of 66440193 is about 405.0204592621.

The spelling of 66440193 in words is "sixty-six million, four hundred forty thousand, one hundred ninety-three".