1131221011 has 2 divisors, whose sum is σ = 1131221012. Its totient is φ = 1131221010.

The previous prime is 1131220999. The next prime is 1131221023. The reversal of 1131221011 is 1101221311.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1131220999) and next prime (1131221023).

It is an emirp because it is prime and its reverse (1101221311) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1131221011 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1131220982 and 1131221000.

It is not a weakly prime, because it can be changed into another prime (1131221071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 565610505 + 565610506.

It is an arithmetic number, because the mean of its divisors is an integer number (565610506).

Almost surely, 2^1131221011 is an apocalyptic number.

1131221011 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131221011 is an equidigital number, since it uses as much as digits as its factorization.

1131221011 is an evil number, because the sum of its binary digits is even.

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

The square root of 1131221011 is about 33633.6291678433. The cubic root of 1131221011 is about 1041.9554589513.

Adding to 1131221011 its reverse (1101221311), we get a palindrome (2232442322).

It can be divided in two parts, 11312 and 21011, that added together give a palindrome (32323).

The spelling of 1131221011 in words is "one billion, one hundred thirty-one million, two hundred twenty-one thousand, eleven".