665261205 has 64 divisors (see below), whose sum is σ = 1239390720. Its totient is φ = 298450944.

The previous prime is 665261161. The next prime is 665261227. The reversal of 665261205 is 502162566.

It is a happy number.

665261205 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 665261205 - 2¹⁴ = 665244821 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2401527 + ... + 2401803.

It is an arithmetic number, because the mean of its divisors is an integer number (19365480).

Almost surely, 2^665261205 is an apocalyptic number.

It is an amenable number.

665261205 is a deficient number, since it is larger than the sum of its proper divisors (574129515).

665261205 is a wasteful number, since it uses less digits than its factorization.

665261205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 665261205 is about 25792.6579669487. The cubic root of 665261205 is about 872.9661409016.

The spelling of 665261205 in words is "six hundred sixty-five million, two hundred sixty-one thousand, two hundred five".