1211111105 has 8 divisors (see below), whose sum is σ = 1458295272. Its totient is φ = 965580928.

The previous prime is 1211111101. The next prime is 1211111107. The reversal of 1211111105 is 5011111121.

It can be written as a sum of positive squares in 4 ways, for example, as 671431744 + 539679361 = 25912^2 + 23231^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211111105 - 2² = 1211111101 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211111105.

It is not an unprimeable number, because it can be changed into a prime (1211111101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 411884 + ... + 414813.

It is an arithmetic number, because the mean of its divisors is an integer number (182286909).

Almost surely, 2^1211111105 is an apocalyptic number.

It is an amenable number.

1211111105 is a deficient number, since it is larger than the sum of its proper divisors (247184167).

1211111105 is an equidigital number, since it uses as much as digits as its factorization.

1211111105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826995.

The product of its (nonzero) digits is 10, while the sum is 14.

The square root of 1211111105 is about 34801.0216085678. The cubic root of 1211111105 is about 1065.9283066700.

Adding to 1211111105 its reverse (5011111121), we get a palindrome (6222222226).

The spelling of 1211111105 in words is "one billion, two hundred eleven million, one hundred eleven thousand, one hundred five".