2006921 has 4 divisors (see below), whose sum is σ = 2293632. Its totient is φ = 1720212.

The previous prime is 2006903. The next prime is 2006923. The reversal of 2006921 is 1296002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2006921 - 2¹⁸ = 1744777 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 2006893 and 2006902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2006923) 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, 143345 + ... + 143358.

It is an arithmetic number, because the mean of its divisors is an integer number (573408).

2^2006921 is an apocalyptic number.

It is an amenable number.

2006921 is a deficient number, since it is larger than the sum of its proper divisors (286711).

2006921 is an equidigital number, since it uses as much as digits as its factorization.

2006921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286710.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 2006921 is about 1416.6583921327. The cubic root of 2006921 is about 126.1372695638.

The spelling of 2006921 in words is "two million, six thousand, nine hundred twenty-one".