669279605 has 4 divisors (see below), whose sum is σ = 803135532. Its totient is φ = 535423680.

The previous prime is 669279571. The next prime is 669279607. The reversal of 669279605 is 506972966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 506972966 = 2 ⋅253486483.

It can be written as a sum of positive squares in 2 ways, for example, as 356378884 + 312900721 = 18878^2 + 17689^2 .

It is not a de Polignac number, because 669279605 - 2⁸ = 669279349 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 (669279607) 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, 66927956 + ... + 66927965.

It is an arithmetic number, because the mean of its divisors is an integer number (200783883).

Almost surely, 2^669279605 is an apocalyptic number.

It is an amenable number.

669279605 is a deficient number, since it is larger than the sum of its proper divisors (133855927).

669279605 is a wasteful number, since it uses less digits than its factorization.

669279605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133855926.

The product of its (nonzero) digits is 1224720, while the sum is 50.

The square root of 669279605 is about 25870.4388250374. The cubic root of 669279605 is about 874.7202828353.

The spelling of 669279605 in words is "six hundred sixty-nine million, two hundred seventy-nine thousand, six hundred five".