2121806 has 8 divisors (see below), whose sum is σ = 3350280. Its totient is φ = 1005048.

The previous prime is 2121803. The next prime is 2121809. The reversal of 2121806 is 6081212.

It is an interprime number because it is at equal distance from previous prime (2121803) and next prime (2121809).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27881 + ... + 27956.

It is an arithmetic number, because the mean of its divisors is an integer number (418785).

2^2121806 is an apocalyptic number.

2121806 is a deficient number, since it is larger than the sum of its proper divisors (1228474).

2121806 is a wasteful number, since it uses less digits than its factorization.

2121806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55858.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 2121806 is about 1456.6420287771. The cubic root of 2121806 is about 128.4996341090.

The spelling of 2121806 in words is "two million, one hundred twenty-one thousand, eight hundred six".