1131431121 has 24 divisors (see below), whose sum is σ = 1705767336. Its totient is φ = 721992960.

The previous prime is 1131431117. The next prime is 1131431123. The reversal of 1131431121 is 1211341311.

It is a happy number.

1131431121 is a `hidden beast` number, since 113 + 1 + 431 + 121 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 50625 + 1131380496 = 225^2 + 33636^2 .

It is not a de Polignac number, because 1131431121 - 2² = 1131431117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1131431094 and 1131431103.

It is not an unprimeable number, because it can be changed into a prime (1131431123) 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, 9370 + ... + 48483.

It is an arithmetic number, because the mean of its divisors is an integer number (71073639).

Almost surely, 2^1131431121 is an apocalyptic number.

It is an amenable number.

1131431121 is a deficient number, since it is larger than the sum of its proper divisors (574336215).

1131431121 is a wasteful number, since it uses less digits than its factorization.

1131431121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57953 (or 57950 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

The square root of 1131431121 is about 33636.7525335012. The cubic root of 1131431121 is about 1042.0199649752.

Adding to 1131431121 its reverse (1211341311), we get a palindrome (2342772432).

The spelling of 1131431121 in words is "one billion, one hundred thirty-one million, four hundred thirty-one thousand, one hundred twenty-one".