1131521 has 4 divisors (see below), whose sum is σ = 1133652. Its totient is φ = 1129392.

The previous prime is 1131509. The next prime is 1131523. The reversal of 1131521 is 1251311.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1251311 = 599 ⋅2089.

It can be written as a sum of positive squares in 2 ways, for example, as 18496 + 1113025 = 136^2 + 1055^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131521 - 2¹⁰ = 1130497 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1131496 and 1131505.

It is not an unprimeable number, because it can be changed into a prime (1131523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 455 + ... + 1571.

It is an arithmetic number, because the mean of its divisors is an integer number (283413).

2^1131521 is an apocalyptic number.

It is an amenable number.

1131521 is a deficient number, since it is larger than the sum of its proper divisors (2131).

1131521 is a wasteful number, since it uses less digits than its factorization.

1131521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2130.

The product of its digits is 30, while the sum is 14.

The square root of 1131521 is about 1063.7297589144. The cubic root of 1131521 is about 104.2047556354.

Adding to 1131521 its reverse (1251311), we get a palindrome (2382832).

The spelling of 1131521 in words is "one million, one hundred thirty-one thousand, five hundred twenty-one".