20985257134784 has 28 divisors (see below), whose sum is σ = 41756087301984. Its totient is φ = 10464038287104.

The previous prime is 20985257134769. The next prime is 20985257134843. The reversal of 20985257134784 is 48743175258902.

It is a self number, because there is not a number n which added to its sum of digits gives 20985257134784.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 446699459 + ... + 446746434.

Almost surely, 2^{20985257134784} is an apocalyptic number.

It is an amenable number.

20985257134784 is a deficient number, since it is larger than the sum of its proper divisors (20770830167200).

20985257134784 is an equidigital number, since it uses as much as digits as its factorization.

20985257134784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 893446272 (or 893446262 counting only the distinct ones).

The product of its (nonzero) digits is 135475200, while the sum is 65.

The spelling of 20985257134784 in words is "twenty trillion, nine hundred eighty-five billion, two hundred fifty-seven million, one hundred thirty-four thousand, seven hundred eighty-four".