2161205630440 has 128 divisors (see below), whose sum is σ = 5246180006400. Its totient is φ = 798701783040.

The previous prime is 2161205630377. The next prime is 2161205630453. The reversal of 2161205630440 is 440365021612.

It is a junction number, because it is equal to n+sod(n) for n = 2161205630396 and 2161205630405.

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, 9929662 + ... + 10144978.

It is an arithmetic number, because the mean of its divisors is an integer number (40985781300).

Almost surely, 2^{2161205630440} is an apocalyptic number.

2161205630440 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 2161205630440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2623090003200).

2161205630440 is an abundant number, since it is smaller than the sum of its proper divisors (3084974375960).

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

2161205630440 is a wasteful number, since it uses less digits than its factorization.

2161205630440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215675 (or 215671 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The spelling of 2161205630440 in words is "two trillion, one hundred sixty-one billion, two hundred five million, six hundred thirty thousand, four hundred forty".