2106921 has 8 divisors (see below), whose sum is σ = 2824704. Its totient is φ = 1396880.

The previous prime is 2106919. The next prime is 2106931. The reversal of 2106921 is 1296012.

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

It is a cyclic number.

It is not a de Polignac number, because 2106921 - 2¹ = 2106919 is a prime.

It is a super-2 number, since 2×2106921² = 8878232200482, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2106901) 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 7 ways as a sum of consecutive naturals, for example, 1266 + ... + 2411.

It is an arithmetic number, because the mean of its divisors is an integer number (353088).

2^2106921 is an apocalyptic number.

It is an amenable number.

2106921 is a deficient number, since it is larger than the sum of its proper divisors (717783).

2106921 is a wasteful number, since it uses less digits than its factorization.

2106921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3871.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 2106921 is about 1451.5236822043. The cubic root of 2106921 is about 128.1984430015.

The spelling of 2106921 in words is "two million, one hundred six thousand, nine hundred twenty-one".