1221131113 has 2 divisors, whose sum is σ = 1221131114. Its totient is φ = 1221131112.

The previous prime is 1221131047. The next prime is 1221131141. The reversal of 1221131113 is 3111311221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1080305424 + 140825689 = 32868^2 + 11867^2 .

It is an emirp because it is prime and its reverse (3111311221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221131113 - 2⁹ = 1221130601 is a prime.

It is a super-3 number, since 3×1221131113³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1221131143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610565556 + 610565557.

It is an arithmetic number, because the mean of its divisors is an integer number (610565557).

Almost surely, 2^1221131113 is an apocalyptic number.

It is an amenable number.

1221131113 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221131113 is an equidigital number, since it uses as much as digits as its factorization.

1221131113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36, while the sum is 16.

The square root of 1221131113 is about 34944.6864773459. The cubic root of 1221131113 is about 1068.8598543395.

Adding to 1221131113 its reverse (3111311221), we get a palindrome (4332442334).

The spelling of 1221131113 in words is "one billion, two hundred twenty-one million, one hundred thirty-one thousand, one hundred thirteen".