1213123311 has 24 divisors (see below), whose sum is σ = 1837639440. Its totient is φ = 799647552.

The previous prime is 1213123297. The next prime is 1213123313. The reversal of 1213123311 is 1133213121.

1213123311 is a `hidden beast` number, since 1 + 21 + 312 + 331 + 1 = 666.

It is not a de Polignac number, because 1213123311 - 2¹¹ = 1213121263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213123313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6420 + ... + 49673.

It is an arithmetic number, because the mean of its divisors is an integer number (76568310).

Almost surely, 2^1213123311 is an apocalyptic number.

1213123311 is a deficient number, since it is larger than the sum of its proper divisors (624516129).

1213123311 is an frugal number, since it uses more digits than its factorization.

1213123311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56197 (or 56185 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 1213123311 is about 34829.9197673495. The cubic root of 1213123311 is about 1066.5183104976.

Adding to 1213123311 its reverse (1133213121), we get a palindrome (2346336432).

The spelling of 1213123311 in words is "one billion, two hundred thirteen million, one hundred twenty-three thousand, three hundred eleven".