2199921 has 4 divisors (see below), whose sum is σ = 2933232. Its totient is φ = 1466612.

The previous prime is 2199917. The next prime is 2199931. The reversal of 2199921 is 1299912.

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 2199921 - 2² = 2199917 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (2199931) 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, 366651 + ... + 366656.

It is an arithmetic number, because the mean of its divisors is an integer number (733308).

2^2199921 is an apocalyptic number.

It is an amenable number.

2199921 is a deficient number, since it is larger than the sum of its proper divisors (733311).

2199921 is an equidigital number, since it uses as much as digits as its factorization.

2199921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733310.

The product of its digits is 2916, while the sum is 33.

The square root of 2199921 is about 1483.2130662855. The cubic root of 2199921 is about 130.0575878980.

Subtracting from 2199921 its reverse (1299912), we obtain a palindrome (900009).

The spelling of 2199921 in words is "two million, one hundred ninety-nine thousand, nine hundred twenty-one".