1131212111221 has 2 divisors, whose sum is σ = 1131212111222. Its totient is φ = 1131212111220.

The previous prime is 1131212111209. The next prime is 1131212111269. The reversal of 1131212111221 is 1221112121311.

It is a m-pointer prime, because the next prime (1131212111269) can be obtained adding 1131212111221 to its product of digits (48).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 782534852100 + 348677259121 = 884610^2 + 590489^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131212111221 - 2⁵ = 1131212111189 is a prime.

It is a super-2 number, since 2×1131212111221² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1131212111201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 565606055610 + 565606055611.

It is an arithmetic number, because the mean of its divisors is an integer number (565606055611).

Almost surely, 2^{1131212111221} is an apocalyptic number.

It is an amenable number.

1131212111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131212111221 is an equidigital number, since it uses as much as digits as its factorization.

1131212111221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48, while the sum is 19.

Adding to 1131212111221 its reverse (1221112121311), we get a palindrome (2352324232532).

The spelling of 1131212111221 in words is "one trillion, one hundred thirty-one billion, two hundred twelve million, one hundred eleven thousand, two hundred twenty-one".