1311222121 has 32 divisors (see below), whose sum is σ = 1556817408. Its totient is φ = 1090928640.

The previous prime is 1311222119. The next prime is 1311222161. The reversal of 1311222121 is 1212221131.

It is not a de Polignac number, because 1311222121 - 2¹ = 1311222119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1311222095 and 1311222104.

It is not an unprimeable number, because it can be changed into a prime (1311222161) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1695891 + ... + 1696663.

It is an arithmetic number, because the mean of its divisors is an integer number (48650544).

Almost surely, 2^1311222121 is an apocalyptic number.

1311222121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1311222121 is a deficient number, since it is larger than the sum of its proper divisors (245595287).

1311222121 is a wasteful number, since it uses less digits than its factorization.

1311222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041.

The product of its digits is 48, while the sum is 16.

The square root of 1311222121 is about 36210.8011648458. The cubic root of 1311222121 is about 1094.5243365394.

Adding to 1311222121 its reverse (1212221131), we get a palindrome (2523443252).

The spelling of 1311222121 in words is "one billion, three hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".