1131221021 has 16 divisors (see below), whose sum is σ = 1369944576. Its totient is φ = 911867136.

The previous prime is 1131221011. The next prime is 1131221023. The reversal of 1131221021 is 1201221311.

It is a cyclic number.

It is not a de Polignac number, because 1131221021 - 2³⁰ = 57479197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1131220987 and 1131221005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131221023) 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, 191900 + ... + 197706.

It is an arithmetic number, because the mean of its divisors is an integer number (85621536).

Almost surely, 2^1131221021 is an apocalyptic number.

It is an amenable number.

1131221021 is a deficient number, since it is larger than the sum of its proper divisors (238723555).

1131221021 is a wasteful number, since it uses less digits than its factorization.

1131221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7468.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 1131221021 is about 33633.6293165040. The cubic root of 1131221021 is about 1041.9554620216.

Adding to 1131221021 its reverse (1201221311), we get a palindrome (2332442332).

The spelling of 1131221021 in words is "one billion, one hundred thirty-one million, two hundred twenty-one thousand, twenty-one".