1131533440 has 64 divisors (see below), whose sum is σ = 2709936000. Its totient is φ = 451800064.

The previous prime is 1131533437. The next prime is 1131533441. The reversal of 1131533440 is 443351311.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (1131533441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 458931 + ... + 461389.

It is an arithmetic number, because the mean of its divisors is an integer number (42342750).

Almost surely, 2^1131533440 is an apocalyptic number.

1131533440 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 1131533440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1354968000).

1131533440 is an abundant number, since it is smaller than the sum of its proper divisors (1578402560).

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

1131533440 is an equidigital number, since it uses as much as digits as its factorization.

1131533440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3197 (or 3185 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 1131533440 is about 33638.2734396402. The cubic root of 1131533440 is about 1042.0513751144.

Adding to 1131533440 its reverse (443351311), we get a palindrome (1574884751).

The spelling of 1131533440 in words is "one billion, one hundred thirty-one million, five hundred thirty-three thousand, four hundred forty".