20775121920 has 528 divisors, whose sum is σ = 85913081280. Its totient is φ = 4747051008.

The previous prime is 20775121919. The next prime is 20775121963. The reversal of 20775121920 is 2912157702.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 6772227 + ... + 6775293.

Almost surely, 2^20775121920 is an apocalyptic number.

20775121920 is a gapful number since it is divisible by the number (20) 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 20775121920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42956540640).

20775121920 is an abundant number, since it is smaller than the sum of its proper divisors (65137959360).

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

20775121920 is a wasteful number, since it uses less digits than its factorization.

20775121920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3115 (or 3084 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The spelling of 20775121920 in words is "twenty billion, seven hundred seventy-five million, one hundred twenty-one thousand, nine hundred twenty".