1801440 has 120 divisors (see below), whose sum is σ = 6403320. Its totient is φ = 476928.

The previous prime is 1801433. The next prime is 1801453. The reversal of 1801440 is 441081.

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 an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12891 + ... + 13029.

It is an arithmetic number, because the mean of its divisors is an integer number (53361).

2^1801440 is an apocalyptic number.

1801440 is a gapful number since it is divisible by the number (10) 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 1801440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3201660).

1801440 is an abundant number, since it is smaller than the sum of its proper divisors (4601880).

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

1801440 is a wasteful number, since it uses less digits than its factorization.

1801440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1801440 is about 1342.1773355261. The cubic root of 1801440 is about 121.6764696757.

The spelling of 1801440 in words is "one million, eight hundred one thousand, four hundred forty".