1531440 has 80 divisors (see below), whose sum is σ = 5282400. Its totient is φ = 407808.

The previous prime is 1531379. The next prime is 1531447. The reversal of 1531440 is 441351.

It is a happy number.

1531440 is nontrivially palindromic in base 11.

It is a tau number, because it is divible by the number of its divisors (80).

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 (1531447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1806 + ... + 2514.

It is an arithmetic number, because the mean of its divisors is an integer number (66030).

2^1531440 is an apocalyptic number.

1531440 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 1531440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2641200).

1531440 is an abundant number, since it is smaller than the sum of its proper divisors (3750960).

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

1531440 is a wasteful number, since it uses less digits than its factorization.

1531440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731 (or 719 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 1531440 is about 1237.5136362885. The cubic root of 1531440 is about 115.2656743582.

Adding to 1531440 its reverse (441351), we get a palindrome (1972791).

It can be divided in two parts, 1 and 531440, that added together give a 12-th power (531441 = 3¹²).

The spelling of 1531440 in words is "one million, five hundred thirty-one thousand, four hundred forty".