20856351744 has 352 divisors, whose sum is σ = 63918803200. Its totient is φ = 6799085568.

The previous prime is 20856351683. The next prime is 20856351779. The reversal of 20856351744 is 44715365802.

20856351744 is a `hidden beast` number, since 2 + 0 + 8 + 5 + 635 + 1 + 7 + 4 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 20856351744.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 150045627 + ... + 150045765.

Almost surely, 2^20856351744 is an apocalyptic number.

20856351744 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20856351744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31959401600).

20856351744 is an abundant number, since it is smaller than the sum of its proper divisors (43062451456).

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

20856351744 is an frugal number, since it uses more digits than its factorization.

20856351744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247 (or 211 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The spelling of 20856351744 in words is "twenty billion, eight hundred fifty-six million, three hundred fifty-one thousand, seven hundred forty-four".