21201944563049 has 2 divisors, whose sum is σ = 21201944563050. Its totient is φ = 21201944563048.

The previous prime is 21201944563039. The next prime is 21201944563061. The reversal of 21201944563049 is 94036544910212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20253060115600 + 948884447449 = 4500340^2 + 974107^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201944563049 - 2³² = 21197649595753 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21201944562988 and 21201944563006.

It is not a weakly prime, because it can be changed into another prime (21201944563039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600972281524 + 10600972281525.

It is an arithmetic number, because the mean of its divisors is an integer number (10600972281525).

Almost surely, 2^{21201944563049} is an apocalyptic number.

It is an amenable number.

21201944563049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201944563049 is an equidigital number, since it uses as much as digits as its factorization.

21201944563049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1866240, while the sum is 50.

The spelling of 21201944563049 in words is "twenty-one trillion, two hundred one billion, nine hundred forty-four million, five hundred sixty-three thousand, forty-nine".