266639005 has 4 divisors (see below), whose sum is σ = 319966812. Its totient is φ = 213311200.

The previous prime is 266639003. The next prime is 266639011. The reversal of 266639005 is 500936662.

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 152448409 + 114190596 = 12347^2 + 10686^2 .

It is not a de Polignac number, because 266639005 - 2¹ = 266639003 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266639003) 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, 26663896 + ... + 26663905.

It is an arithmetic number, because the mean of its divisors is an integer number (79991703).

Almost surely, 2^266639005 is an apocalyptic number.

It is an amenable number.

266639005 is a deficient number, since it is larger than the sum of its proper divisors (53327807).

266639005 is an equidigital number, since it uses as much as digits as its factorization.

266639005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53327806.

The product of its (nonzero) digits is 58320, while the sum is 37.

The square root of 266639005 is about 16329.0846344797. The cubic root of 266639005 is about 643.6373330962.

The spelling of 266639005 in words is "two hundred sixty-six million, six hundred thirty-nine thousand, five".