1940821 has 2 divisors, whose sum is σ = 1940822. Its totient is φ = 1940820.

The previous prime is 1940797. The next prime is 1940833. The reversal of 1940821 is 1280491.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1347921 + 592900 = 1161^2 + 770^2 .

It is a cyclic number.

It is not a de Polignac number, because 1940821 - 2¹¹ = 1938773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1940881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 970410 + 970411.

It is an arithmetic number, because the mean of its divisors is an integer number (970411).

2^1940821 is an apocalyptic number.

It is an amenable number.

1940821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1940821 is an equidigital number, since it uses as much as digits as its factorization.

1940821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 1940821 is about 1393.1335183679. The cubic root of 1940821 is about 124.7369615411.

The spelling of 1940821 in words is "one million, nine hundred forty thousand, eight hundred twenty-one".