21401440220417 has 2 divisors, whose sum is σ = 21401440220418. Its totient is φ = 21401440220416.

The previous prime is 21401440220371. The next prime is 21401440220443. The reversal of 21401440220417 is 71402204410412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17639252407921 + 3762187812496 = 4199911^2 + 1939636^2 .

It is a cyclic number.

It is not a de Polignac number, because 21401440220417 - 2²⁴ = 21401423443201 is a prime.

It is not a weakly prime, because it can be changed into another prime (21401440220617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700720110208 + 10700720110209.

It is an arithmetic number, because the mean of its divisors is an integer number (10700720110209).

Almost surely, 2^{21401440220417} is an apocalyptic number.

It is an amenable number.

21401440220417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21401440220417 is an equidigital number, since it uses as much as digits as its factorization.

21401440220417 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14336, while the sum is 32.

Adding to 21401440220417 its reverse (71402204410412), we get a palindrome (92803644630829).

The spelling of 21401440220417 in words is "twenty-one trillion, four hundred one billion, four hundred forty million, two hundred twenty thousand, four hundred seventeen".