1131121021 has 4 divisors (see below), whose sum is σ = 1131285052. Its totient is φ = 1130956992.

The previous prime is 1131121009. The next prime is 1131121039. The reversal of 1131121021 is 1201211311.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1201211311 = 487 ⋅2466553.

It can be written as a sum of positive squares in 2 ways, for example, as 1079122500 + 51998521 = 32850^2 + 7211^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131121021 - 2¹¹ = 1131118973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1131120992 and 1131121010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131121721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71196 + ... + 85621.

It is an arithmetic number, because the mean of its divisors is an integer number (282821263).

Almost surely, 2^1131121021 is an apocalyptic number.

It is an amenable number.

1131121021 is a deficient number, since it is larger than the sum of its proper divisors (164031).

1131121021 is an equidigital number, since it uses as much as digits as its factorization.

1131121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164030.

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1131121021 is about 33632.1426763149. The cubic root of 1131121021 is about 1041.9247581436.

Adding to 1131121021 its reverse (1201211311), we get a palindrome (2332332332).

The spelling of 1131121021 in words is "one billion, one hundred thirty-one million, one hundred twenty-one thousand, twenty-one".