1211213311 has 48 divisors (see below), whose sum is σ = 1635361920. Its totient is φ = 884520000.

The previous prime is 1211213287. The next prime is 1211213329. The reversal of 1211213311 is 1133121121.

It is a happy number.

It is not a de Polignac number, because 1211213311 - 2¹⁹ = 1210689023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211213111) 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 47 ways as a sum of consecutive naturals, for example, 1033756 + ... + 1034926.

It is an arithmetic number, because the mean of its divisors is an integer number (34070040).

Almost surely, 2^1211213311 is an apocalyptic number.

1211213311 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1211213311 is a deficient number, since it is larger than the sum of its proper divisors (424148609).

1211213311 is a wasteful number, since it uses less digits than its factorization.

1211213311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1316 (or 1309 counting only the distinct ones).

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

The square root of 1211213311 is about 34802.4900114920. The cubic root of 1211213311 is about 1065.9582904878.

Adding to 1211213311 its reverse (1133121121), we get a palindrome (2344334432).

The spelling of 1211213311 in words is "one billion, two hundred eleven million, two hundred thirteen thousand, three hundred eleven".