2196821 has 8 divisors (see below), whose sum is σ = 2455488. Its totient is φ = 1948000.

The previous prime is 2196809. The next prime is 2196829. The reversal of 2196821 is 1286912.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2196821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2196829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1985 + ... + 2886.

It is an arithmetic number, because the mean of its divisors is an integer number (306936).

2^2196821 is an apocalyptic number.

It is an amenable number.

2196821 is a deficient number, since it is larger than the sum of its proper divisors (258667).

2196821 is a wasteful number, since it uses less digits than its factorization.

2196821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4923.

The product of its digits is 1728, while the sum is 29.

The square root of 2196821 is about 1482.1676693276. The cubic root of 2196821 is about 129.9964693321.

Subtracting from 2196821 its reverse (1286912), we obtain a palindrome (909909).

The spelling of 2196821 in words is "two million, one hundred ninety-six thousand, eight hundred twenty-one".