1540240 has 40 divisors (see below), whose sum is σ = 3859128. Its totient is φ = 568320.

The previous prime is 1540229. The next prime is 1540243. The reversal of 1540240 is 420451.

It can be written as a sum of positive squares in 4 ways, for example, as 12544 + 1527696 = 112^2 + 1236^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1540243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 300 + ... + 1780.

2^1540240 is an apocalyptic number.

1540240 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 1540240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1929564).

1540240 is an abundant number, since it is smaller than the sum of its proper divisors (2318888).

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

1540240 is a wasteful number, since it uses less digits than its factorization.

1540240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1507 (or 1501 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 1540240 is about 1241.0640595876. The cubic root of 1540240 is about 115.4860336804.

Adding to 1540240 its reverse (420451), we get a palindrome (1960691).

The spelling of 1540240 in words is "one million, five hundred forty thousand, two hundred forty".