1111000021 has 4 divisors (see below), whose sum is σ = 1111810572. Its totient is φ = 1110189472.

The previous prime is 1110999983. The next prime is 1111000039. The reversal of 1111000021 is 1200001111.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 818760996 + 292239025 = 28614^2 + 17095^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1111000021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1110999968 and 1111000013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111000081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 403216 + ... + 405961.

It is an arithmetic number, because the mean of its divisors is an integer number (277952643).

Almost surely, 2^1111000021 is an apocalyptic number.

It is an amenable number.

1111000021 is a deficient number, since it is larger than the sum of its proper divisors (810551).

1111000021 is an equidigital number, since it uses as much as digits as its factorization.

1111000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810550.

The product of its (nonzero) digits is 2, while the sum is 7.

The square root of 1111000021 is about 33331.6669400137. Note that the first 3 decimals coincide. The cubic root of 1111000021 is about 1035.7096492204.

Adding to 1111000021 its reverse (1200001111), we get a palindrome (2311001132).

The spelling of 1111000021 in words is "one billion, one hundred eleven million, twenty-one", and thus it is an aban number.