1940021 has 4 divisors (see below), whose sum is σ = 1992492. Its totient is φ = 1887552.

The previous prime is 1939999. The next prime is 1940041. The reversal of 1940021 is 1200491.

1940021 = 124² + 125² + ... + 197².

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1653796 + 286225 = 1286^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 1940021 - 2¹⁰ = 1938997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1940041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26180 + ... + 26253.

It is an arithmetic number, because the mean of its divisors is an integer number (498123).

2^1940021 is an apocalyptic number.

It is an amenable number.

1940021 is a deficient number, since it is larger than the sum of its proper divisors (52471).

1940021 is an equidigital number, since it uses as much as digits as its factorization.

1940021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52470.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 1940021 is about 1392.8463662587. The cubic root of 1940021 is about 124.7198204646.

The spelling of 1940021 in words is "one million, nine hundred forty thousand, twenty-one".