640685577627 has 6 divisors (see below), whose sum is σ = 925434723252. Its totient is φ = 427123718412.

The previous prime is 640685577619. The next prime is 640685577629. The reversal of 640685577627 is 726775586046.

640685577627 is a `hidden beast` number, since 6 + 4 + 0 + 6 + 8 + 557 + 76 + 2 + 7 = 666.

It is not a de Polignac number, because 640685577627 - 2³ = 640685577619 is a prime.

It is a super-2 number, since 2×640685577627² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640685577629) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35593643193 + ... + 35593643210.

It is an arithmetic number, because the mean of its divisors is an integer number (154239120542).

Almost surely, 2^640685577627 is an apocalyptic number.

640685577627 is a deficient number, since it is larger than the sum of its proper divisors (284749145625).

640685577627 is a wasteful number, since it uses less digits than its factorization.

640685577627 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71187286409 (or 71187286406 counting only the distinct ones).

The product of its (nonzero) digits is 118540800, while the sum is 63.

The spelling of 640685577627 in words is "six hundred forty billion, six hundred eighty-five million, five hundred seventy-seven thousand, six hundred twenty-seven".