1100000021 has 4 divisors (see below), whose sum is σ = 1100162700. Its totient is φ = 1099837344.

The previous prime is 1100000017. The next prime is 1100000051. The reversal of 1100000021 is 1200000011.

It is a happy number.

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 403567921 + 696432100 = 20089^2 + 26390^2 .

It is a cyclic number.

It is not a de Polignac number, because 1100000021 - 2² = 1100000017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1099999960 and 1100000014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1100000051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70736 + ... + 84873.

It is an arithmetic number, because the mean of its divisors is an integer number (275040675).

Almost surely, 2^1100000021 is an apocalyptic number.

It is an amenable number.

1100000021 is a deficient number, since it is larger than the sum of its proper divisors (162679).

1100000021 is an equidigital number, since it uses as much as digits as its factorization.

1100000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162678.

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 1100000021 is about 33166.2482201409. The cubic root of 1100000021 is about 1032.2801220254.

Adding to 1100000021 its reverse (1200000011), we get a palindrome (2300000032).

The spelling of 1100000021 in words is "one billion, one hundred million, twenty-one", and thus it is an aban number.