21002220199997 has 2 divisors, whose sum is σ = 21002220199998. Its totient is φ = 21002220199996.

The previous prime is 21002220199967. The next prime is 21002220200029. The reversal of 21002220199997 is 79999102220012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20307046119556 + 695174080441 = 4506334^2 + 833771^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002220199997 - 2¹⁴ = 21002220183613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002220199907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501110099998 + 10501110099999.

It is an arithmetic number, because the mean of its divisors is an integer number (10501110099999).

Almost surely, 2^{21002220199997} is an apocalyptic number.

It is an amenable number.

21002220199997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002220199997 is an equidigital number, since it uses as much as digits as its factorization.

21002220199997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 734832, while the sum is 53.

The spelling of 21002220199997 in words is "twenty-one trillion, two billion, two hundred twenty million, one hundred ninety-nine thousand, nine hundred ninety-seven".