2121789942720 has 672 divisors, whose sum is σ = 9161398471680. Its totient is φ = 439477125120.

The previous prime is 2121789942677. The next prime is 2121789942787. The reversal of 2121789942720 is 272499871212.

2121789942720 is a `hidden beast` number, since 2 + 121 + 7 + 8 + 99 + 427 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×2121789942720² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

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, 8689500 + ... + 8930340.

It is an arithmetic number, because the mean of its divisors is an integer number (13633033440).

Almost surely, 2^{2121789942720} is an apocalyptic number.

2121789942720 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 2121789942720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4580699235840).

2121789942720 is an abundant number, since it is smaller than the sum of its proper divisors (7039608528960).

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

2121789942720 is a wasteful number, since it uses less digits than its factorization.

2121789942720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240913 (or 240900 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 54.

The spelling of 2121789942720 in words is "two trillion, one hundred twenty-one billion, seven hundred eighty-nine million, nine hundred forty-two thousand, seven hundred twenty".