21010120100197 has 2 divisors, whose sum is σ = 21010120100198. Its totient is φ = 21010120100196.

The previous prime is 21010120100171. The next prime is 21010120100273. The reversal of 21010120100197 is 79100102101012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18572428061476 + 2437692038721 = 4309574^2 + 1561311^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010120100197 - 2⁷ = 21010120100069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010120100147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505060050098 + 10505060050099.

It is an arithmetic number, because the mean of its divisors is an integer number (10505060050099).

Almost surely, 2^{21010120100197} is an apocalyptic number.

It is an amenable number.

21010120100197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010120100197 is an equidigital number, since it uses as much as digits as its factorization.

21010120100197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 25.

The spelling of 21010120100197 in words is "twenty-one trillion, ten billion, one hundred twenty million, one hundred thousand, one hundred ninety-seven".