1211123131 has 4 divisors (see below), whose sum is σ = 1222881712. Its totient is φ = 1199364552.

The previous prime is 1211123077. The next prime is 1211123189. The reversal of 1211123131 is 1313211121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1313211121 = 17 ⋅77247713.

It is a cyclic number.

It is not a de Polignac number, because 1211123131 - 2¹¹ = 1211121083 is a prime.

It is a super-2 number, since 2×1211123131² = 2933638476886486322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211123191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5879136 + ... + 5879341.

It is an arithmetic number, because the mean of its divisors is an integer number (305720428).

Almost surely, 2^1211123131 is an apocalyptic number.

1211123131 is a deficient number, since it is larger than the sum of its proper divisors (11758581).

1211123131 is a wasteful number, since it uses less digits than its factorization.

1211123131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11758580.

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

The square root of 1211123131 is about 34801.1943904229. The cubic root of 1211123131 is about 1065.9318347832.

Adding to 1211123131 its reverse (1313211121), we get a palindrome (2524334252).

The spelling of 1211123131 in words is "one billion, two hundred eleven million, one hundred twenty-three thousand, one hundred thirty-one".