21001002220111 has 2 divisors, whose sum is σ = 21001002220112. Its totient is φ = 21001002220110.

The previous prime is 21001002220091. The next prime is 21001002220123. The reversal of 21001002220111 is 11102220010012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21001002220111 - 2²¹ = 21001000122959 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001002220091 and 21001002220100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001002220171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500501110055 + 10500501110056.

It is an arithmetic number, because the mean of its divisors is an integer number (10500501110056).

Almost surely, 2^{21001002220111} is an apocalyptic number.

21001002220111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001002220111 is an equidigital number, since it uses as much as digits as its factorization.

21001002220111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21001002220111 its reverse (11102220010012), we get a palindrome (32103222230123).

The spelling of 21001002220111 in words is "twenty-one trillion, one billion, two million, two hundred twenty thousand, one hundred eleven".