20849620849 has 2 divisors, whose sum is σ = 20849620850. Its totient is φ = 20849620848.

The previous prime is 20849620837. The next prime is 20849620889. The reversal of 20849620849 is 94802694802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16332840000 + 4516780849 = 127800^2 + 67207^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20849620849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20849620796 and 20849620805.

It is not a weakly prime, because it can be changed into another prime (20849620889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10424810424 + 10424810425.

It is an arithmetic number, because the mean of its divisors is an integer number (10424810425).

Almost surely, 2^20849620849 is an apocalyptic number.

It is an amenable number.

20849620849 is a deficient number, since it is larger than the sum of its proper divisors (1).

20849620849 is an equidigital number, since it uses as much as digits as its factorization.

20849620849 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1990656, while the sum is 52.

The spelling of 20849620849 in words is "twenty billion, eight hundred forty-nine million, six hundred twenty thousand, eight hundred forty-nine".