1131221031 has 16 divisors (see below), whose sum is σ = 1638896640. Its totient is φ = 691407360.

The previous prime is 1131221023. The next prime is 1131221053. The reversal of 1131221031 is 1301221311.

It is a happy number.

It is not a de Polignac number, because 1131221031 - 2³ = 1131221023 is a prime.

It is a super-2 number, since 2×1131221031² = 2559322041953405922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1131221031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131221011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 318330 + ... + 321863.

It is an arithmetic number, because the mean of its divisors is an integer number (102431040).

Almost surely, 2^1131221031 is an apocalyptic number.

1131221031 is a deficient number, since it is larger than the sum of its proper divisors (507675609).

1131221031 is a wasteful number, since it uses less digits than its factorization.

1131221031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640246.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1131221031 is about 33633.6294651648. The cubic root of 1131221031 is about 1041.9554650919.

Adding to 1131221031 its reverse (1301221311), we get a palindrome (2432442342).

The spelling of 1131221031 in words is "one billion, one hundred thirty-one million, two hundred twenty-one thousand, thirty-one".