21202100197 has 2 divisors, whose sum is σ = 21202100198. Its totient is φ = 21202100196.

The previous prime is 21202100167. The next prime is 21202100207. The reversal of 21202100197 is 79100120212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14254210881 + 6947889316 = 119391^2 + 83354^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21202100197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202100147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601050098 + 10601050099.

It is an arithmetic number, because the mean of its divisors is an integer number (10601050099).

Almost surely, 2^21202100197 is an apocalyptic number.

It is an amenable number.

21202100197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202100197 is an equidigital number, since it uses as much as digits as its factorization.

21202100197 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 25.

The spelling of 21202100197 in words is "twenty-one billion, two hundred two million, one hundred thousand, one hundred ninety-seven".