11211221111 has 8 divisors (see below), whose sum is σ = 11814314880. Its totient is φ = 10609430328.

The previous prime is 11211221101. The next prime is 11211221137. The reversal of 11211221111 is 11112211211.

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 11211221111 - 2¹⁰ = 11211220087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211221101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 308051 + ... + 342516.

It is an arithmetic number, because the mean of its divisors is an integer number (1476789360).

Almost surely, 2^11211221111 is an apocalyptic number.

11211221111 is a deficient number, since it is larger than the sum of its proper divisors (603093769).

11211221111 is an equidigital number, since it uses as much as digits as its factorization.

11211221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651493.

The product of its digits is 8, while the sum is 14.

Adding to 11211221111 its reverse (11112211211), we get a palindrome (22323432322).

The spelling of 11211221111 in words is "eleven billion, two hundred eleven million, two hundred twenty-one thousand, one hundred eleven".