640665063 has 24 divisors (see below), whose sum is σ = 935151360. Its totient is φ = 422632080.

The previous prime is 640665061. The next prime is 640665121. The reversal of 640665063 is 360566046.

640665063 is a `hidden beast` number, since 640 + 6 + 6 + 5 + 0 + 6 + 3 = 666.

It is not a de Polignac number, because 640665063 - 2¹ = 640665061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640665061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 616098 + ... + 617136.

It is an arithmetic number, because the mean of its divisors is an integer number (38964640).

Almost surely, 2^640665063 is an apocalyptic number.

640665063 is a deficient number, since it is larger than the sum of its proper divisors (294486297).

640665063 is a wasteful number, since it uses less digits than its factorization.

640665063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1699 (or 1696 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The square root of 640665063 is about 25311.3623299893. The cubic root of 640665063 is about 862.0722799230.

The spelling of 640665063 in words is "six hundred forty million, six hundred sixty-five thousand, sixty-three".