20644688684 has 24 divisors (see below), whose sum is σ = 38975162688. Its totient is φ = 9531841280.

The previous prime is 20644688653. The next prime is 20644688711. The reversal of 20644688684 is 48688644602.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2860532 + ... + 2867739.

It is an arithmetic number, because the mean of its divisors is an integer number (1623965112).

Almost surely, 2^20644688684 is an apocalyptic number.

It is an amenable number.

20644688684 is a deficient number, since it is larger than the sum of its proper divisors (18330474004).

20644688684 is a wasteful number, since it uses less digits than its factorization.

20644688684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5728345 (or 5728343 counting only the distinct ones).

The product of its (nonzero) digits is 14155776, while the sum is 56.

The spelling of 20644688684 in words is "twenty billion, six hundred forty-four million, six hundred eighty-eight thousand, six hundred eighty-four".