2198021 has 4 divisors (see below), whose sum is σ = 2512032. Its totient is φ = 1884012.

The previous prime is 2198011. The next prime is 2198029. The reversal of 2198021 is 1208912.

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 a de Polignac number, because none of the positive numbers 2^k-2198021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2198029) 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, 156995 + ... + 157008.

It is an arithmetic number, because the mean of its divisors is an integer number (628008).

2^2198021 is an apocalyptic number.

It is an amenable number.

2198021 is a deficient number, since it is larger than the sum of its proper divisors (314011).

2198021 is an equidigital number, since it uses as much as digits as its factorization.

2198021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314010.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 2198021 is about 1482.5724265613. The cubic root of 2198021 is about 130.0201349483.

The spelling of 2198021 in words is "two million, one hundred ninety-eight thousand, twenty-one".