1531320 has 64 divisors (see below), whose sum is σ = 5253120. Its totient is φ = 349824.

The previous prime is 1531303. The next prime is 1531331. The reversal of 1531320 is 231351.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1531320.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72 + ... + 1751.

It is an arithmetic number, because the mean of its divisors is an integer number (82080).

2^1531320 is an apocalyptic number.

1531320 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 1531320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2626560).

1531320 is an abundant number, since it is smaller than the sum of its proper divisors (3721800).

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

1531320 is a wasteful number, since it uses less digits than its factorization.

1531320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1844 (or 1840 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 1531320 is about 1237.4651510245. The cubic root of 1531320 is about 115.2626636314.

Adding to 1531320 its reverse (231351), we get a palindrome (1762671).

The spelling of 1531320 in words is "one million, five hundred thirty-one thousand, three hundred twenty".