21110102009 has 2 divisors, whose sum is σ = 21110102010. Its totient is φ = 21110102008.

The previous prime is 21110101997. The next prime is 21110102021. The reversal of 21110102009 is 90020101112.

It is a balanced prime because it is at equal distance from previous prime (21110101997) and next prime (21110102021).

It can be written as a sum of positive squares in only one way, i.e., 20899039225 + 211062784 = 144565^2 + 14528^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110102009 - 2⁴ = 21110101993 is a prime.

It is not a weakly prime, because it can be changed into another prime (21110101009) 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 as a sum of consecutive naturals, namely, 10555051004 + 10555051005.

It is an arithmetic number, because the mean of its divisors is an integer number (10555051005).

Almost surely, 2^21110102009 is an apocalyptic number.

It is an amenable number.

21110102009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110102009 is an equidigital number, since it uses as much as digits as its factorization.

21110102009 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 17.

The spelling of 21110102009 in words is "twenty-one billion, one hundred ten million, one hundred two thousand, nine".