11111220021121 has 16 divisors (see below), whose sum is σ = 12850215036480. Its totient is φ = 9495174638080.

The previous prime is 11111220021113. The next prime is 11111220021133. The reversal of 11111220021121 is 12112002211111.

It is a cyclic number.

It is not a de Polignac number, because 11111220021121 - 2³ = 11111220021113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11111220021095 and 11111220021104.

It is not an unprimeable number, because it can be changed into a prime (11111220021151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36572011 + ... + 36874576.

It is an arithmetic number, because the mean of its divisors is an integer number (803138439780).

Almost surely, 2^{11111220021121} is an apocalyptic number.

11111220021121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11111220021121 is a deficient number, since it is larger than the sum of its proper divisors (1738995015359).

11111220021121 is a wasteful number, since it uses less digits than its factorization.

11111220021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73447424.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 11111220021121 its reverse (12112002211111), we get a palindrome (23223222232232).

The spelling of 11111220021121 in words is "eleven trillion, one hundred eleven billion, two hundred twenty million, twenty-one thousand, one hundred twenty-one".