1212111011 has 4 divisors (see below), whose sum is σ = 1212676152. Its totient is φ = 1211545872.

The previous prime is 1212110989. The next prime is 1212111037. The reversal of 1212111011 is 1101112121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1101112121 = 157 ⋅7013453.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212111011 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212110983 and 1212111001.

It is not an unprimeable number, because it can be changed into a prime (1212111071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 279341 + ... + 283646.

It is an arithmetic number, because the mean of its divisors is an integer number (303169038).

Almost surely, 2^1212111011 is an apocalyptic number.

1212111011 is a deficient number, since it is larger than the sum of its proper divisors (565141).

1212111011 is an equidigital number, since it uses as much as digits as its factorization.

1212111011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565140.

The product of its (nonzero) digits is 4, while the sum is 11.

The square root of 1212111011 is about 34815.3846883817. The cubic root of 1212111011 is about 1066.2215731644.

Adding to 1212111011 its reverse (1101112121), we get a palindrome (2313223132).

It can be divided in two parts, 12121 and 11011, that multiplied together give a palindrome (133464331).

The spelling of 1212111011 in words is "one billion, two hundred twelve million, one hundred eleven thousand, eleven".