640055065 has 8 divisors (see below), whose sum is σ = 827148168. Its totient is φ = 472656000.

The previous prime is 640055023. The next prime is 640055089. The reversal of 640055065 is 560550046.

640055065 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 4460544 + 635594521 = 2112^2 + 25211^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640055065 - 2⁷ = 640054937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4923436 + ... + 4923565.

It is an arithmetic number, because the mean of its divisors is an integer number (103393521).

Almost surely, 2^640055065 is an apocalyptic number.

640055065 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

640055065 is a deficient number, since it is larger than the sum of its proper divisors (187093103).

640055065 is a wasteful number, since it uses less digits than its factorization.

640055065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9847019.

The product of its (nonzero) digits is 18000, while the sum is 31.

The square root of 640055065 is about 25299.3095755596. The cubic root of 640055065 is about 861.7985907094.

The spelling of 640055065 in words is "six hundred forty million, fifty-five thousand, sixty-five".