805221889 has 2 divisors, whose sum is σ = 805221890. Its totient is φ = 805221888.

The previous prime is 805221887. The next prime is 805221943. The reversal of 805221889 is 988122508.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 474891264 + 330330625 = 21792^2 + 18175^2 .

It is a cyclic number.

It is not a de Polignac number, because 805221889 - 2¹ = 805221887 is a prime.

Together with 805221887, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (805221887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402610944 + 402610945.

It is an arithmetic number, because the mean of its divisors is an integer number (402610945).

Almost surely, 2^805221889 is an apocalyptic number.

It is an amenable number.

805221889 is a deficient number, since it is larger than the sum of its proper divisors (1).

805221889 is an equidigital number, since it uses as much as digits as its factorization.

805221889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 92160, while the sum is 43.

The square root of 805221889 is about 28376.4319286270. The cubic root of 805221889 is about 930.3332096940. Note that the first 3 decimals are identical.

The spelling of 805221889 in words is "eight hundred five million, two hundred twenty-one thousand, eight hundred eighty-nine".