1996821 has 12 divisors (see below), whose sum is σ = 2908672. Its totient is φ = 1319976.

The previous prime is 1996817. The next prime is 1996829. The reversal of 1996821 is 1286991.

1996821 = T₁₁₀ + T₁₁₁ + ... + T₂₃₆.

It is not a de Polignac number, because 1996821 - 2² = 1996817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1996829) 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 in 11 ways as a sum of consecutive naturals, for example, 270 + ... + 2016.

2^1996821 is an apocalyptic number.

It is an amenable number.

1996821 is a deficient number, since it is larger than the sum of its proper divisors (911851).

1996821 is a wasteful number, since it uses less digits than its factorization.

1996821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1880 (or 1877 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 1996821 is about 1413.0891691610. The cubic root of 1996821 is about 125.9253147723.

The spelling of 1996821 in words is "one million, nine hundred ninety-six thousand, eight hundred twenty-one".