2161111680 has 1152 divisors, whose sum is σ = 10158220800. Its totient is φ = 418037760.

The previous prime is 2161111669. The next prime is 2161111727. The reversal of 2161111680 is 861111612.

It is a tau number, because it is divible by the number of its divisors (1152).

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 143 ways as a sum of consecutive naturals, for example, 69713265 + ... + 69713295.

It is an arithmetic number, because the mean of its divisors is an integer number (8817900).

Almost surely, 2^2161111680 is an apocalyptic number.

2161111680 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 2161111680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5079110400).

2161111680 is an abundant number, since it is smaller than the sum of its proper divisors (7997109120).

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

2161111680 is a wasteful number, since it uses less digits than its factorization.

2161111680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 27.

The square root of 2161111680 is about 46487.7583886339. The cubic root of 2161111680 is about 1292.8825391294.

The spelling of 2161111680 in words is "two billion, one hundred sixty-one million, one hundred eleven thousand, six hundred eighty".