640964631064 has 16 divisors (see below), whose sum is σ = 1201849689600. Its totient is φ = 320471380512.

The previous prime is 640964631061. The next prime is 640964631071. The reversal of 640964631064 is 460136469046.

It is a junction number, because it is equal to n+sod(n) for n = 640964630999 and 640964631017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640964631061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1115032 + ... + 1589095.

It is an arithmetic number, because the mean of its divisors is an integer number (75115605600).

Almost surely, 2^640964631064 is an apocalyptic number.

It is an amenable number.

640964631064 is a deficient number, since it is larger than the sum of its proper divisors (560885058536).

640964631064 is a wasteful number, since it uses less digits than its factorization.

640964631064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2733762 (or 2733758 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 49.

The spelling of 640964631064 in words is "six hundred forty billion, nine hundred sixty-four million, six hundred thirty-one thousand, sixty-four".