11211111021 has 32 divisors (see below), whose sum is σ = 16422912000. Its totient is φ = 6746492480.

The previous prime is 11211111017. The next prime is 11211111047. The reversal of 11211111021 is 12011111211.

It is a cyclic number.

It is not a de Polignac number, because 11211111021 - 2² = 11211111017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11211110988 and 11211111006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211111071) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3892660 + ... + 3895538.

It is an arithmetic number, because the mean of its divisors is an integer number (513216000).

Almost surely, 2^11211111021 is an apocalyptic number.

11211111021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11211111021 is a deficient number, since it is larger than the sum of its proper divisors (5211800979).

11211111021 is a wasteful number, since it uses less digits than its factorization.

11211111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3689.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 11211111021 its reverse (12011111211), we get a palindrome (23222222232).

The spelling of 11211111021 in words is "eleven billion, two hundred eleven million, one hundred eleven thousand, twenty-one".