640186165 has 16 divisors (see below), whose sum is σ = 796535280. Its totient is φ = 493355520.

The previous prime is 640186159. The next prime is 640186207. The reversal of 640186165 is 561681046.

640186165 is digitally balanced in base 2 and base 6, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 36108081 + 604078084 = 6009^2 + 24578^2 .

It is not a de Polignac number, because 640186165 - 2⁹ = 640185653 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61435 + ... + 71095.

It is an arithmetic number, because the mean of its divisors is an integer number (49783455).

Almost surely, 2^640186165 is an apocalyptic number.

It is an amenable number.

640186165 is a deficient number, since it is larger than the sum of its proper divisors (156349115).

640186165 is a wasteful number, since it uses less digits than its factorization.

640186165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10152.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 640186165 is about 25301.9004226955. The cubic root of 640186165 is about 861.8574263151.

The spelling of 640186165 in words is "six hundred forty million, one hundred eighty-six thousand, one hundred sixty-five".