2161440 has 144 divisors (see below), whose sum is σ = 7862400. Its totient is φ = 539136.

The previous prime is 2161433. The next prime is 2161447. The reversal of 2161440 is 441612.

It is an interprime number because it is at equal distance from previous prime (2161433) and next prime (2161447).

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (2161447) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27321 + ... + 27399.

It is an arithmetic number, because the mean of its divisors is an integer number (54600).

2^2161440 is an apocalyptic number.

2161440 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 2161440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3931200).

2161440 is an abundant number, since it is smaller than the sum of its proper divisors (5700960).

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

2161440 is a wasteful number, since it uses less digits than its factorization.

2161440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 2161440 is about 1470.1836619960. The cubic root of 2161440 is about 129.2948008166.

It can be divided in two parts, 2161 and 440, that added together give a square (2601 = 51²).

The spelling of 2161440 in words is "two million, one hundred sixty-one thousand, four hundred forty".