21331031297 has 2 divisors, whose sum is σ = 21331031298. Its totient is φ = 21331031296.

The previous prime is 21331031279. The next prime is 21331031363. The reversal of 21331031297 is 79213013312.

Together with previous prime (21331031279) 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., 15819602176 + 5511429121 = 125776^2 + 74239^2 .

It is a cyclic number.

It is not a de Polignac number, because 21331031297 - 2⁶ = 21331031233 is a prime.

It is not a weakly prime, because it can be changed into another prime (21331031797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665515648 + 10665515649.

It is an arithmetic number, because the mean of its divisors is an integer number (10665515649).

Almost surely, 2^21331031297 is an apocalyptic number.

It is an amenable number.

21331031297 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331031297 is an equidigital number, since it uses as much as digits as its factorization.

21331031297 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 32.

The spelling of 21331031297 in words is "twenty-one billion, three hundred thirty-one million, thirty-one thousand, two hundred ninety-seven".