20778799079808 has 512 divisors, whose sum is σ = 76477494067200. Its totient is φ = 5395770132480.

The previous prime is 20778799079789. The next prime is 20778799079833. The reversal of 20778799079808 is 80897099787702.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1576174785 + ... + 1576187967.

It is an arithmetic number, because the mean of its divisors is an integer number (149370105600).

Almost surely, 2^{20778799079808} is an apocalyptic number.

20778799079808 is a gapful number since it is divisible by the number (28) 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 20778799079808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38238747033600).

20778799079808 is an abundant number, since it is smaller than the sum of its proper divisors (55698694987392).

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

20778799079808 is a wasteful number, since it uses less digits than its factorization.

20778799079808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19147 (or 19129 counting only the distinct ones).

The product of its (nonzero) digits is 1792336896, while the sum is 81.

The spelling of 20778799079808 in words is "twenty trillion, seven hundred seventy-eight billion, seven hundred ninety-nine million, seventy-nine thousand, eight hundred eight".