21144823838417 has 2 divisors, whose sum is σ = 21144823838418. Its totient is φ = 21144823838416.

The previous prime is 21144823838407. The next prime is 21144823838429. The reversal of 21144823838417 is 71483832844112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21024875213521 + 119948624896 = 4585289^2 + 346336^2 .

It is a cyclic number.

It is not a de Polignac number, because 21144823838417 - 2⁶ = 21144823838353 is a prime.

It is not a weakly prime, because it can be changed into another prime (21144823838407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572411919208 + 10572411919209.

It is an arithmetic number, because the mean of its divisors is an integer number (10572411919209).

Almost surely, 2^{21144823838417} is an apocalyptic number.

It is an amenable number.

21144823838417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21144823838417 is an equidigital number, since it uses as much as digits as its factorization.

21144823838417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8257536, while the sum is 56.

The spelling of 21144823838417 in words is "twenty-one trillion, one hundred forty-four billion, eight hundred twenty-three million, eight hundred thirty-eight thousand, four hundred seventeen".