640011285 has 36 divisors (see below), whose sum is σ = 1118398788. Its totient is φ = 338577408.

The previous prime is 640011277. The next prime is 640011287. The reversal of 640011285 is 582110046.

640011285 is a `hidden beast` number, since 640 + 0 + 1 + 12 + 8 + 5 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 2852721 + 637158564 = 1689^2 + 25242^2 .

It is not a de Polignac number, because 640011285 - 2³ = 640011277 is a prime.

It is a super-2 number, since 2×640011285² = 819228889854702450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640011287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1108917 + ... + 1109493.

It is an arithmetic number, because the mean of its divisors is an integer number (31066633).

Almost surely, 2^640011285 is an apocalyptic number.

It is an amenable number.

640011285 is a deficient number, since it is larger than the sum of its proper divisors (478387503).

640011285 is a wasteful number, since it uses less digits than its factorization.

640011285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902 (or 742 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 640011285 is about 25298.4443197601. Note that the first 3 decimals coincide. The cubic root of 640011285 is about 861.7789411487.

The spelling of 640011285 in words is "six hundred forty million, eleven thousand, two hundred eighty-five".