2297821 has 4 divisors (see below), whose sum is σ = 2329372. Its totient is φ = 2266272.

The previous prime is 2297819. The next prime is 2297843. The reversal of 2297821 is 1287922.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1287922 = 2 ⋅643961.

It can be written as a sum of positive squares in 2 ways, for example, as 1416100 + 881721 = 1190^2 + 939^2 .

It is a cyclic number.

It is not a de Polignac number, because 2297821 - 2¹ = 2297819 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 (2297881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15666 + ... + 15811.

It is an arithmetic number, because the mean of its divisors is an integer number (582343).

2^2297821 is an apocalyptic number.

It is an amenable number.

2297821 is a deficient number, since it is larger than the sum of its proper divisors (31551).

2297821 is an equidigital number, since it uses as much as digits as its factorization.

2297821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31550.

The product of its digits is 4032, while the sum is 31.

The square root of 2297821 is about 1515.8565235536. The cubic root of 2297821 is about 131.9589135978.

The spelling of 2297821 in words is "two million, two hundred ninety-seven thousand, eight hundred twenty-one".