20640864384 has 96 divisors (see below), whose sum is σ = 67881440640. Its totient is φ = 5897387520.

The previous prime is 20640864383. The next prime is 20640864403. The reversal of 20640864384 is 48346804602.

20640864384 is a `hidden beast` number, since 206 + 4 + 0 + 8 + 6 + 438 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (20640864383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1271752 + ... + 1287879.

It is an arithmetic number, because the mean of its divisors is an integer number (707098340).

Almost surely, 2^20640864384 is an apocalyptic number.

20640864384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20640864384 is an abundant number, since it is smaller than the sum of its proper divisors (47240576256).

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

20640864384 is a wasteful number, since it uses less digits than its factorization.

20640864384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2559658 (or 2559643 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 45.

The spelling of 20640864384 in words is "twenty billion, six hundred forty million, eight hundred sixty-four thousand, three hundred eighty-four".