20779978912 has 192 divisors, whose sum is σ = 54104537088. Its totient is φ = 7615872000.

The previous prime is 20779978907. The next prime is 20779978927. The reversal of 20779978912 is 21987997702.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3453987 + ... + 3459997.

It is an arithmetic number, because the mean of its divisors is an integer number (281794464).

Almost surely, 2^20779978912 is an apocalyptic number.

20779978912 is a gapful number since it is divisible by the number (22) 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 20779978912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27052268544).

20779978912 is an abundant number, since it is smaller than the sum of its proper divisors (33324558176).

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

20779978912 is a wasteful number, since it uses less digits than its factorization.

20779978912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6123 (or 6115 counting only the distinct ones).

The product of its (nonzero) digits is 8001504, while the sum is 61.

The spelling of 20779978912 in words is "twenty billion, seven hundred seventy-nine million, nine hundred seventy-eight thousand, nine hundred twelve".