665261055 has 12 divisors (see below), whose sum is σ = 1153119240. Its totient is φ = 354805872.

The previous prime is 665261053. The next prime is 665261057. The reversal of 665261055 is 550162566.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (665261053) and next prime (665261057).

It is not a de Polignac number, because 665261055 - 2¹ = 665261053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665261053) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7391745 + ... + 7391834.

It is an arithmetic number, because the mean of its divisors is an integer number (96093270).

Almost surely, 2^665261055 is an apocalyptic number.

665261055 is a deficient number, since it is larger than the sum of its proper divisors (487858185).

665261055 is a wasteful number, since it uses less digits than its factorization.

665261055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14783590 (or 14783587 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 665261055 is about 25792.6550591443. The cubic root of 665261055 is about 872.9660752908.

The spelling of 665261055 in words is "six hundred sixty-five million, two hundred sixty-one thousand, fifty-five".