850900021 has 2 divisors, whose sum is σ = 850900022. Its totient is φ = 850900020.

The previous prime is 850899983. The next prime is 850900033. The reversal of 850900021 is 120009058.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 824264100 + 26635921 = 28710^2 + 5161^2 .

It is a cyclic number.

It is not a de Polignac number, because 850900021 - 2¹³ = 850891829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (850900051) 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, 425450010 + 425450011.

It is an arithmetic number, because the mean of its divisors is an integer number (425450011).

Almost surely, 2^850900021 is an apocalyptic number.

It is an amenable number.

850900021 is a deficient number, since it is larger than the sum of its proper divisors (1).

850900021 is an equidigital number, since it uses as much as digits as its factorization.

850900021 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 850900021 is about 29170.1906233058. The cubic root of 850900021 is about 947.6024570181.

Adding to 850900021 its reverse (120009058), we get a palindrome (970909079).

The spelling of 850900021 in words is "eight hundred fifty million, nine hundred thousand, twenty-one".