21201120197 has 2 divisors, whose sum is σ = 21201120198. Its totient is φ = 21201120196.

The previous prime is 21201120179. The next prime is 21201120203. The reversal of 21201120197 is 79102110212.

Together with previous prime (21201120179) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21044144356 + 156975841 = 145066^2 + 12529^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201120197 - 2⁶ = 21201120133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201120097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600560098 + 10600560099.

It is an arithmetic number, because the mean of its divisors is an integer number (10600560099).

Almost surely, 2^21201120197 is an apocalyptic number.

It is an amenable number.

21201120197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201120197 is an equidigital number, since it uses as much as digits as its factorization.

21201120197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 26.

The spelling of 21201120197 in words is "twenty-one billion, two hundred one million, one hundred twenty thousand, one hundred ninety-seven".