21002120202197 has 2 divisors, whose sum is σ = 21002120202198. Its totient is φ = 21002120202196.

The previous prime is 21002120202061. The next prime is 21002120202211. The reversal of 21002120202197 is 79120202120012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20705494008241 + 296626193956 = 4550329^2 + 544634^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002120202197 - 2¹⁰ = 21002120201173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002120202797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501060101098 + 10501060101099.

It is an arithmetic number, because the mean of its divisors is an integer number (10501060101099).

Almost surely, 2^{21002120202197} is an apocalyptic number.

It is an amenable number.

21002120202197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002120202197 is an equidigital number, since it uses as much as digits as its factorization.

21002120202197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 29.

The spelling of 21002120202197 in words is "twenty-one trillion, two billion, one hundred twenty million, two hundred two thousand, one hundred ninety-seven".