21202131122197 has 2 divisors, whose sum is σ = 21202131122198. Its totient is φ = 21202131122196.

The previous prime is 21202131122173. The next prime is 21202131122201. The reversal of 21202131122197 is 79122113120212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15698386970161 + 5503744152036 = 3962119^2 + 2346006^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21202131122197 is a prime.

It is a super-2 number, since 2×21202131122197² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202131122297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601065561098 + 10601065561099.

It is an arithmetic number, because the mean of its divisors is an integer number (10601065561099).

Almost surely, 2^{21202131122197} is an apocalyptic number.

It is an amenable number.

21202131122197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202131122197 is an equidigital number, since it uses as much as digits as its factorization.

21202131122197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 34.

The spelling of 21202131122197 in words is "twenty-one trillion, two hundred two billion, one hundred thirty-one million, one hundred twenty-two thousand, one hundred ninety-seven".