11100120021 has 6 divisors (see below), whose sum is σ = 16033506710. Its totient is φ = 7400080008.

The previous prime is 11100120013. The next prime is 11100120043. The reversal of 11100120021 is 12002100111.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 10875569796 + 224550225 = 104286^2 + 14985^2 .

It is not a de Polignac number, because 11100120021 - 2³ = 11100120013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 1233346669 = 11100120021 / (1 + 1 + 1 + 0 + 0 + 1 + 2 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11100119985 and 11100120012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11100120001) 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 5 ways as a sum of consecutive naturals, for example, 616673326 + ... + 616673343.

Almost surely, 2^11100120021 is an apocalyptic number.

It is an amenable number.

11100120021 is a deficient number, since it is larger than the sum of its proper divisors (4933386689).

11100120021 is a wasteful number, since it uses less digits than its factorization.

11100120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1233346675 (or 1233346672 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 11100120021 its reverse (12002100111), we get a palindrome (23102220132).

The spelling of 11100120021 in words is "eleven billion, one hundred million, one hundred twenty thousand, twenty-one".