21251065633361 has 2 divisors, whose sum is σ = 21251065633362. Its totient is φ = 21251065633360.

The previous prime is 21251065633333. The next prime is 21251065633373. The reversal of 21251065633361 is 16333656015212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21203087111761 + 47978521600 = 4604681^2 + 219040^2 .

It is a cyclic number.

It is not a de Polignac number, because 21251065633361 - 2²² = 21251061439057 is a prime.

It is not a weakly prime, because it can be changed into another prime (21251065633961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10625532816680 + 10625532816681.

It is an arithmetic number, because the mean of its divisors is an integer number (10625532816681).

Almost surely, 2^{21251065633361} is an apocalyptic number.

It is an amenable number.

21251065633361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21251065633361 is an equidigital number, since it uses as much as digits as its factorization.

21251065633361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 583200, while the sum is 44.

The spelling of 21251065633361 in words is "twenty-one trillion, two hundred fifty-one billion, sixty-five million, six hundred thirty-three thousand, three hundred sixty-one".