20997578708496 has 480 divisors, whose sum is σ = 66188026195200. Its totient is φ = 6169405132800.

The previous prime is 20997578708417. The next prime is 20997578708531. The reversal of 20997578708496 is 69480787579902.

20997578708496 is a `hidden beast` number, since 2 + 0 + 9 + 9 + 7 + 57 + 8 + 70 + 8 + 496 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7144462195 + ... + 7144465133.

It is an arithmetic number, because the mean of its divisors is an integer number (137891721240).

Almost surely, 2^{20997578708496} is an apocalyptic number.

20997578708496 is a gapful number since it is divisible by the number (26) 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 20997578708496, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33094013097600).

20997578708496 is an abundant number, since it is smaller than the sum of its proper divisors (45190447486704).

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

20997578708496 is a wasteful number, since it uses less digits than its factorization.

20997578708496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4399 (or 4390 counting only the distinct ones).

The product of its (nonzero) digits is 3840721920, while the sum is 81.

The spelling of 20997578708496 in words is "twenty trillion, nine hundred ninety-seven billion, five hundred seventy-eight million, seven hundred eight thousand, four hundred ninety-six".