21845876849 has 2 divisors, whose sum is σ = 21845876850. Its totient is φ = 21845876848.

The previous prime is 21845876839. The next prime is 21845876881. The reversal of 21845876849 is 94867854812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11394495025 + 10451381824 = 106745^2 + 102232^2 .

It is a cyclic number.

It is not a de Polignac number, because 21845876849 - 2¹⁶ = 21845811313 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21845876791 and 21845876800.

It is not a weakly prime, because it can be changed into another prime (21845876839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10922938424 + 10922938425.

It is an arithmetic number, because the mean of its divisors is an integer number (10922938425).

Almost surely, 2^21845876849 is an apocalyptic number.

It is an amenable number.

21845876849 is a deficient number, since it is larger than the sum of its proper divisors (1).

21845876849 is an equidigital number, since it uses as much as digits as its factorization.

21845876849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30965760, while the sum is 62.

The spelling of 21845876849 in words is "twenty-one billion, eight hundred forty-five million, eight hundred seventy-six thousand, eight hundred forty-nine".