21221112220109 has 2 divisors, whose sum is σ = 21221112220110. Its totient is φ = 21221112220108.

The previous prime is 21221112220031. The next prime is 21221112220163. The reversal of 21221112220109 is 90102221112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13206522910084 + 8014589310025 = 3634078^2 + 2831005^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221112220109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221117220109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610556110054 + 10610556110055.

It is an arithmetic number, because the mean of its divisors is an integer number (10610556110055).

Almost surely, 2^{21221112220109} is an apocalyptic number.

It is an amenable number.

21221112220109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221112220109 is an equidigital number, since it uses as much as digits as its factorization.

21221112220109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 26.

The spelling of 21221112220109 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twelve million, two hundred twenty thousand, one hundred nine".