21155211311441 has 2 divisors, whose sum is σ = 21155211311442. Its totient is φ = 21155211311440.

The previous prime is 21155211311407. The next prime is 21155211311477. The reversal of 21155211311441 is 14411311255112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13110590931025 + 8044620380416 = 3620855^2 + 2836304^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21155211311441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21155211311398 and 21155211311407.

It is not a weakly prime, because it can be changed into another prime (21155211314441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577605655720 + 10577605655721.

It is an arithmetic number, because the mean of its divisors is an integer number (10577605655721).

Almost surely, 2^{21155211311441} is an apocalyptic number.

It is an amenable number.

21155211311441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21155211311441 is an equidigital number, since it uses as much as digits as its factorization.

21155211311441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4800, while the sum is 32.

Adding to 21155211311441 its reverse (14411311255112), we get a palindrome (35566522566553).

The spelling of 21155211311441 in words is "twenty-one trillion, one hundred fifty-five billion, two hundred eleven million, three hundred eleven thousand, four hundred forty-one".