2107921 has 4 divisors (see below), whose sum is σ = 2124144. Its totient is φ = 2091700.

The previous prime is 2107913. The next prime is 2107939. The reversal of 2107921 is 1297012.

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 2107921 - 2³ = 2107913 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

2107921 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2107892 and 2107901.

It is not an unprimeable number, because it can be changed into a prime (2107961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7915 + ... + 8176.

It is an arithmetic number, because the mean of its divisors is an integer number (531036).

2^2107921 is an apocalyptic number.

It is an amenable number.

2107921 is a deficient number, since it is larger than the sum of its proper divisors (16223).

2107921 is a wasteful number, since it uses less digits than its factorization.

2107921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16222.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 2107921 is about 1451.8681069574. The cubic root of 2107921 is about 128.2187219087.

The spelling of 2107921 in words is "two million, one hundred seven thousand, nine hundred twenty-one".