1540440 has 96 divisors (see below), whose sum is σ = 5475600. Its totient is φ = 372480.

The previous prime is 1540423. The next prime is 1540447. The reversal of 1540440 is 440451.

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 (1540447) 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, 3766 + ... + 4154.

2^1540440 is an apocalyptic number.

1540440 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 1540440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2737800).

1540440 is an abundant number, since it is smaller than the sum of its proper divisors (3935160).

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

1540440 is a wasteful number, since it uses less digits than its factorization.

1540440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417 (or 410 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 1540440 is about 1241.1446329900. The cubic root of 1540440 is about 115.4910320805.

Adding to 1540440 its reverse (440451), we get a palindrome (1980891).

The spelling of 1540440 in words is "one million, five hundred forty thousand, four hundred forty".