2206921 has 4 divisors (see below), whose sum is σ = 2278144. Its totient is φ = 2135700.

The previous prime is 2206909. The next prime is 2206927. The reversal of 2206921 is 1296022.

It is a happy number.

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-2206921 is a prime.

It is a Duffinian number.

2206921 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2206892 and 2206901.

It is not an unprimeable number, because it can be changed into a prime (2206927) 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, 35565 + ... + 35626.

It is an arithmetic number, because the mean of its divisors is an integer number (569536).

2^2206921 is an apocalyptic number.

It is an amenable number.

2206921 is a deficient number, since it is larger than the sum of its proper divisors (71223).

2206921 is an equidigital number, since it uses as much as digits as its factorization.

2206921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71222.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 2206921 is about 1485.5709340183. The cubic root of 2206921 is about 130.1953866651.

The spelling of 2206921 in words is "two million, two hundred six thousand, nine hundred twenty-one".