1123123101221 has 12 divisors (see below), whose sum is σ = 1234545486636. Its totient is φ = 1020989344320.

The previous prime is 1123123101197. The next prime is 1123123101223. The reversal of 1123123101221 is 1221013213211.

It can be written as a sum of positive squares in 2 ways, for example, as 838618209121 + 284504892100 = 915761^2 + 533390^2 .

It is not a de Polignac number, because 1123123101221 - 2¹⁸ = 1123122839077 is a prime.

It is a super-2 number, since 2×1123123101221² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1123123101193 and 1123123101202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1123123101223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4353185 + ... + 4603961.

It is an arithmetic number, because the mean of its divisors is an integer number (102878790553).

Almost surely, 2^{1123123101221} is an apocalyptic number.

1123123101221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1123123101221 is a deficient number, since it is larger than the sum of its proper divisors (111422385415).

1123123101221 is a wasteful number, since it uses less digits than its factorization.

1123123101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287812 (or 287801 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 1123123101221 its reverse (1221013213211), we get a palindrome (2344136314432).

The spelling of 1123123101221 in words is "one trillion, one hundred twenty-three billion, one hundred twenty-three million, one hundred one thousand, two hundred twenty-one".