1131232555521 has 24 divisors (see below), whose sum is σ = 1660436415560. Its totient is φ = 742005328896.

The previous prime is 1131232555511. The next prime is 1131232555547. The reversal of 1131232555521 is 1255552321311.

1131232555521 is a `hidden beast` number, since 1 + 1 + 3 + 123 + 2 + 5 + 5 + 5 + 521 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 391006343025 + 740226212496 = 625305^2 + 860364^2 .

It is not a de Polignac number, because 1131232555521 - 2³³ = 1122642620929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1131232555511) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1836196 + ... + 2373621.

Almost surely, 2^{1131232555521} is an apocalyptic number.

It is an amenable number.

1131232555521 is a deficient number, since it is larger than the sum of its proper divisors (529203860039).

1131232555521 is a wasteful number, since it uses less digits than its factorization.

1131232555521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4210305 (or 4210302 counting only the distinct ones).

The product of its digits is 45000, while the sum is 36.

Adding to 1131232555521 its reverse (1255552321311), we get a palindrome (2386784876832).

The spelling of 1131232555521 in words is "one trillion, one hundred thirty-one billion, two hundred thirty-two million, five hundred fifty-five thousand, five hundred twenty-one".