1131231221221 has 16 divisors (see below), whose sum is σ = 1209730302000. Its totient is φ = 1054062284800.

The previous prime is 1131231221209. The next prime is 1131231221231. The reversal of 1131231221221 is 1221221321311.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1019844225 + 1130211376996 = 31935^2 + 1063114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131231221221 - 2¹⁵ = 1131231188453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1131231221192 and 1131231221201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131231221231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34751265 + ... + 34783801.

It is an arithmetic number, because the mean of its divisors is an integer number (75608143875).

Almost surely, 2^{1131231221221} is an apocalyptic number.

It is an amenable number.

1131231221221 is a deficient number, since it is larger than the sum of its proper divisors (78499080779).

1131231221221 is a wasteful number, since it uses less digits than its factorization.

1131231221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52904.

The product of its digits is 288, while the sum is 22.

Adding to 1131231221221 its reverse (1221221321311), we get a palindrome (2352452542532).

The spelling of 1131231221221 in words is "one trillion, one hundred thirty-one billion, two hundred thirty-one million, two hundred twenty-one thousand, two hundred twenty-one".