2805217421 has 2 divisors, whose sum is σ = 2805217422. Its totient is φ = 2805217420.

The previous prime is 2805217411. The next prime is 2805217423. The reversal of 2805217421 is 1247125082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1641384196 + 1163833225 = 40514^2 + 34115^2 .

It is a cyclic number.

It is not a de Polignac number, because 2805217421 - 2¹⁰ = 2805216397 is a prime.

Together with 2805217423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2805217423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1402608710 + 1402608711.

It is an arithmetic number, because the mean of its divisors is an integer number (1402608711).

Almost surely, 2^2805217421 is an apocalyptic number.

It is an amenable number.

2805217421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2805217421 is an equidigital number, since it uses as much as digits as its factorization.

2805217421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8960, while the sum is 32.

The square root of 2805217421 is about 52964.3032711656. The cubic root of 2805217421 is about 1410.3346490359.

The spelling of 2805217421 in words is "two billion, eight hundred five million, two hundred seventeen thousand, four hundred twenty-one".