1131564 has 48 divisors (see below), whose sum is σ = 3180800. Its totient is φ = 305856.

The previous prime is 1131553. The next prime is 1131569. The reversal of 1131564 is 4651311.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 1131564.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131569) 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 15 ways as a sum of consecutive naturals, for example, 1242 + ... + 1950.

2^1131564 is an apocalyptic number.

1131564 is a gapful number since it is divisible by the number (14) 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 1131564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1590400).

1131564 is an abundant number, since it is smaller than the sum of its proper divisors (2049236).

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

1131564 is a wasteful number, since it uses less digits than its factorization.

1131564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742 (or 740 counting only the distinct ones).

The product of its digits is 360, while the sum is 21.

The square root of 1131564 is about 1063.7499706228. The cubic root of 1131564 is about 104.2060756131.

Adding to 1131564 its reverse (4651311), we get a palindrome (5782875).

The spelling of 1131564 in words is "one million, one hundred thirty-one thousand, five hundred sixty-four".