1021100209 has 2 divisors, whose sum is σ = 1021100210. Its totient is φ = 1021100208.

The previous prime is 1021100191. The next prime is 1021100263. The reversal of 1021100209 is 9020011201.

1021100209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1019397184 + 1703025 = 31928^2 + 1305^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021100209 - 2⁵ = 1021100177 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021100192 and 1021100201.

It is not a weakly prime, because it can be changed into another prime (1021100009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510550104 + 510550105.

It is an arithmetic number, because the mean of its divisors is an integer number (510550105).

Almost surely, 2^1021100209 is an apocalyptic number.

It is an amenable number.

1021100209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021100209 is an equidigital number, since it uses as much as digits as its factorization.

1021100209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 1021100209 is about 31954.6586431462. The cubic root of 1021100209 is about 1006.9845060987.

The spelling of 1021100209 in words is "one billion, twenty-one million, one hundred thousand, two hundred nine".