64663656321 has 16 divisors (see below), whose sum is σ = 94987482048. Its totient is φ = 38802072000.

The previous prime is 64663656301. The next prime is 64663656349. The reversal of 64663656321 is 12365636646.

It is not a de Polignac number, because 64663656321 - 2⁹ = 64663655809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64663656301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9697186 + ... + 9703851.

It is an arithmetic number, because the mean of its divisors is an integer number (5936717628).

Almost surely, 2^64663656321 is an apocalyptic number.

It is an amenable number.

64663656321 is a deficient number, since it is larger than the sum of its proper divisors (30323825727).

64663656321 is a wasteful number, since it uses less digits than its factorization.

64663656321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19401152.

The product of its digits is 2799360, while the sum is 48.

The spelling of 64663656321 in words is "sixty-four billion, six hundred sixty-three million, six hundred fifty-six thousand, three hundred twenty-one".