20865659580 has 72 divisors (see below), whose sum is σ = 67015598832. Its totient is φ = 5236870656.

The previous prime is 20865659579. The next prime is 20865659611. The reversal of 20865659580 is 8595656802.

20865659580 is a `hidden beast` number, since 2 + 0 + 8 + 6 + 5 + 6 + 59 + 580 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3406362 + ... + 3412481.

It is an arithmetic number, because the mean of its divisors is an integer number (930772206).

Almost surely, 2^20865659580 is an apocalyptic number.

20865659580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20865659580 is an abundant number, since it is smaller than the sum of its proper divisors (46149939252).

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

20865659580 is a wasteful number, since it uses less digits than its factorization.

20865659580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6818875 (or 6818870 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 54.

The spelling of 20865659580 in words is "twenty billion, eight hundred sixty-five million, six hundred fifty-nine thousand, five hundred eighty".