1111020021 has 6 divisors (see below), whose sum is σ = 1604806710. Its totient is φ = 740680008.

The previous prime is 1111020017. The next prime is 1111020049. The reversal of 1111020021 is 1200201111.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 929579121 + 181440900 = 30489^2 + 13470^2 .

It is not a de Polignac number, because 1111020021 - 2² = 1111020017 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: 123446669 = 1111020021 / (1 + 1 + 1 + 1 + 0 + 2 + 0 + 0 + 2 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 1111019985 and 1111020012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111020011) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 61723326 + ... + 61723343.

It is an arithmetic number, because the mean of its divisors is an integer number (267467785).

Almost surely, 2^1111020021 is an apocalyptic number.

It is an amenable number.

1111020021 is a deficient number, since it is larger than the sum of its proper divisors (493786689).

1111020021 is a wasteful number, since it uses less digits than its factorization.

1111020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123446675 (or 123446672 counting only the distinct ones).

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

The square root of 1111020021 is about 33331.9669536618. The cubic root of 1111020021 is about 1035.7158640624.

Adding to 1111020021 its reverse (1200201111), we get a palindrome (2311221132).

The spelling of 1111020021 in words is "one billion, one hundred eleven million, twenty thousand, twenty-one".