21010211197 has 2 divisors, whose sum is σ = 21010211198. Its totient is φ = 21010211196.

The previous prime is 21010211177. The next prime is 21010211227. The reversal of 21010211197 is 79111201012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15394357476 + 5615853721 = 124074^2 + 74939^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010211197 - 2⁷ = 21010211069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010211137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505105598 + 10505105599.

It is an arithmetic number, because the mean of its divisors is an integer number (10505105599).

Almost surely, 2^21010211197 is an apocalyptic number.

It is an amenable number.

21010211197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010211197 is an equidigital number, since it uses as much as digits as its factorization.

21010211197 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21010211197 in words is "twenty-one billion, ten million, two hundred eleven thousand, one hundred ninety-seven".