1850021 has 2 divisors, whose sum is σ = 1850022.
Its totient is φ = 1850020.
The previous prime is 1849979. The next prime is 1850029. The reversal of 1850021 is 1200581.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1020100 + 829921 = 1010^2 + 911^2
It is an emirp because it is prime and its reverse (1200581) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 1850021 - 210 = 1848997 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is a Curzon number.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (1850029) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 925010 + 925011.
It is an arithmetic number, because the mean of its divisors is an integer number (925011).
21850021 is an apocalyptic number.
It is an amenable number.
1850021 is a deficient number, since it is larger than the sum of its proper divisors (1).
1850021 is an equidigital number, since it uses as much as digits as its factorization.
1850021 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 80, while the sum is 17.
The square root of 1850021 is about 1360.1547706052.
The cubic root of 1850021 is about 122.7605671151.
The spelling of 1850021 in words is "one million, eight hundred fifty thousand, twenty-one".