2143440 has 120 divisors (see below), whose sum is σ = 7785960. Its totient is φ = 525312.

The previous prime is 2143417. The next prime is 2143441. The reversal of 2143440 is 443412.

It can be written as a sum of positive squares in 4 ways, for example, as 304704 + 1838736 = 552^2 + 1356^2 .

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2143441) 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, 9246 + ... + 9474.

It is an arithmetic number, because the mean of its divisors is an integer number (64883).

2^2143440 is an apocalyptic number.

2143440 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 2143440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3892980).

2143440 is an abundant number, since it is smaller than the sum of its proper divisors (5642520).

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

2143440 is a wasteful number, since it uses less digits than its factorization.

2143440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 2143440 is about 1464.0491795018. The cubic root of 2143440 is about 128.9348869160.

Adding to 2143440 its reverse (443412), we get a palindrome (2586852).

The spelling of 2143440 in words is "two million, one hundred forty-three thousand, four hundred forty".