21342312197 has 2 divisors, whose sum is σ = 21342312198. Its totient is φ = 21342312196.

The previous prime is 21342312179. The next prime is 21342312239. The reversal of 21342312197 is 79121324312.

Together with previous prime (21342312179) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11208668641 + 10133643556 = 105871^2 + 100666^2 .

It is a cyclic number.

It is not a de Polignac number, because 21342312197 - 2⁶ = 21342312133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21342312097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671156098 + 10671156099.

It is an arithmetic number, because the mean of its divisors is an integer number (10671156099).

Almost surely, 2^21342312197 is an apocalyptic number.

It is an amenable number.

21342312197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21342312197 is an equidigital number, since it uses as much as digits as its factorization.

21342312197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 35.

The spelling of 21342312197 in words is "twenty-one billion, three hundred forty-two million, three hundred twelve thousand, one hundred ninety-seven".