20643584028 has 24 divisors (see below), whose sum is σ = 48217692432. Its totient is φ = 6874147584.

The previous prime is 20643583991. The next prime is 20643584029. The reversal of 20643584028 is 82048534602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643584029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 868675 + ... + 892122.

It is an arithmetic number, because the mean of its divisors is an integer number (2009070518).

Almost surely, 2^20643584028 is an apocalyptic number.

It is an amenable number.

20643584028 is an abundant number, since it is smaller than the sum of its proper divisors (27574108404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20643584028 is a wasteful number, since it uses less digits than its factorization.

20643584028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1761781 (or 1761779 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 42.

The spelling of 20643584028 in words is "twenty billion, six hundred forty-three million, five hundred eighty-four thousand, twenty-eight".