50009821 has 2 divisors, whose sum is σ = 50009822. Its totient is φ = 50009820.

The previous prime is 50009819. The next prime is 50009831. The reversal of 50009821 is 12890005.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49857721 + 152100 = 7061^2 + 390^2 .

It is a cyclic number.

It is not a de Polignac number, because 50009821 - 2¹ = 50009819 is a prime.

Together with 50009819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (50009831) 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, 25004910 + 25004911.

It is an arithmetic number, because the mean of its divisors is an integer number (25004911).

Almost surely, 2^50009821 is an apocalyptic number.

It is an amenable number.

50009821 is a deficient number, since it is larger than the sum of its proper divisors (1).

50009821 is an equidigital number, since it uses as much as digits as its factorization.

50009821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 50009821 is about 7071.7622273377. The cubic root of 50009821 is about 368.4272688672.

Adding to 50009821 its reverse (12890005), we get a palindrome (62899826).

The spelling of 50009821 in words is "fifty million, nine thousand, eight hundred twenty-one".