666224905 has 4 divisors (see below), whose sum is σ = 799469892. Its totient is φ = 532979920.

The previous prime is 666224869. The next prime is 666224921. The reversal of 666224905 is 509422666.

666224905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75151561 + 591073344 = 8669^2 + 24312^2 .

It is not a de Polignac number, because 666224905 - 2⁹ = 666224393 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66622486 + ... + 66622495.

It is an arithmetic number, because the mean of its divisors is an integer number (199867473).

Almost surely, 2^666224905 is an apocalyptic number.

It is an amenable number.

666224905 is a deficient number, since it is larger than the sum of its proper divisors (133244987).

666224905 is a wasteful number, since it uses less digits than its factorization.

666224905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133244986.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 666224905 is about 25811.3328791831. The cubic root of 666224905 is about 873.3874649190.

The spelling of 666224905 in words is "six hundred sixty-six million, two hundred twenty-four thousand, nine hundred five".