428847821 has 2 divisors, whose sum is σ = 428847822. Its totient is φ = 428847820.

The previous prime is 428847791. The next prime is 428847833. The reversal of 428847821 is 128748824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 407595721 + 21252100 = 20189^2 + 4610^2 .

It is a cyclic number.

It is not a de Polignac number, because 428847821 - 2²⁶ = 361738957 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (428847851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214423910 + 214423911.

It is an arithmetic number, because the mean of its divisors is an integer number (214423911).

Almost surely, 2^428847821 is an apocalyptic number.

It is an amenable number.

428847821 is a deficient number, since it is larger than the sum of its proper divisors (1).

428847821 is an equidigital number, since it uses as much as digits as its factorization.

428847821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 229376, while the sum is 44.

The square root of 428847821 is about 20708.6412156858. The cubic root of 428847821 is about 754.1094838051.

It can be divided in two parts, 42884 and 7821, that added together give a palindrome (50705).

The spelling of 428847821 in words is "four hundred twenty-eight million, eight hundred forty-seven thousand, eight hundred twenty-one".