1996921 has 4 divisors (see below), whose sum is σ = 2002932. Its totient is φ = 1990912.

The previous prime is 1996903. The next prime is 1996933. The reversal of 1996921 is 1296991.

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 469225 + 1527696 = 685^2 + 1236^2 .

It is a cyclic number.

It is not a de Polignac number, because 1996921 - 2⁷ = 1996793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1996901) 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 in 3 ways as a sum of consecutive naturals, for example, 2476 + ... + 3181.

It is an arithmetic number, because the mean of its divisors is an integer number (500733).

2^1996921 is an apocalyptic number.

It is an amenable number.

1996921 is a deficient number, since it is larger than the sum of its proper divisors (6011).

1996921 is an equidigital number, since it uses as much as digits as its factorization.

1996921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6010.

The product of its digits is 8748, while the sum is 37.

The square root of 1996921 is about 1413.1245521892. The cubic root of 1996921 is about 125.9274168338.

The spelling of 1996921 in words is "one million, nine hundred ninety-six thousand, nine hundred twenty-one".