21408881260841 has 2 divisors, whose sum is σ = 21408881260842. Its totient is φ = 21408881260840.

The previous prime is 21408881260777. The next prime is 21408881260843. The reversal of 21408881260841 is 14806218880412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14845447174441 + 6563434086400 = 3852979^2 + 2561920^2 .

It is a cyclic number.

It is not a de Polignac number, because 21408881260841 - 2⁶ = 21408881260777 is a prime.

Together with 21408881260843, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21408881260843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10704440630420 + 10704440630421.

It is an arithmetic number, because the mean of its divisors is an integer number (10704440630421).

Almost surely, 2^{21408881260841} is an apocalyptic number.

It is an amenable number.

21408881260841 is a deficient number, since it is larger than the sum of its proper divisors (1).

21408881260841 is an equidigital number, since it uses as much as digits as its factorization.

21408881260841 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1572864, while the sum is 53.

The spelling of 21408881260841 in words is "twenty-one trillion, four hundred eight billion, eight hundred eighty-one million, two hundred sixty thousand, eight hundred forty-one".