2805885821 has 2 divisors, whose sum is σ = 2805885822. Its totient is φ = 2805885820.

The previous prime is 2805885811. The next prime is 2805885847. The reversal of 2805885821 is 1285885082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2804232025 + 1653796 = 52955^2 + 1286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2805885821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2805885811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1402942910 + 1402942911.

It is an arithmetic number, because the mean of its divisors is an integer number (1402942911).

Almost surely, 2^2805885821 is an apocalyptic number.

It is an amenable number.

2805885821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2805885821 is an equidigital number, since it uses as much as digits as its factorization.

2805885821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 409600, while the sum is 47.

The square root of 2805885821 is about 52970.6128055925. The cubic root of 2805885821 is about 1410.4466537612.

The spelling of 2805885821 in words is "two billion, eight hundred five million, eight hundred eighty-five thousand, eight hundred twenty-one".