2213845 has 4 divisors (see below), whose sum is σ = 2656620. Its totient is φ = 1771072.

The previous prime is 2213843. The next prime is 2213867. The reversal of 2213845 is 5483122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5483122 = 2 ⋅2741561.

It can be written as a sum of positive squares in 2 ways, for example, as 358801 + 1855044 = 599^2 + 1362^2 .

It is a cyclic number.

It is not a de Polignac number, because 2213845 - 2¹ = 2213843 is a prime.

It is a super-2 number, since 2×2213845² = 9802219368050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2213843) 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, 221380 + ... + 221389.

It is an arithmetic number, because the mean of its divisors is an integer number (664155).

2^2213845 is an apocalyptic number.

It is an amenable number.

2213845 is a deficient number, since it is larger than the sum of its proper divisors (442775).

2213845 is an equidigital number, since it uses as much as digits as its factorization.

2213845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442774.

The product of its digits is 1920, while the sum is 25.

The square root of 2213845 is about 1487.8995261778. The cubic root of 2213845 is about 130.3314029726.

Adding to 2213845 its reverse (5483122), we get a palindrome (7696967).

It can be divided in two parts, 22 and 13845, that multiplied together give a triangular number (304590 = T₇₈₀).

The spelling of 2213845 in words is "two million, two hundred thirteen thousand, eight hundred forty-five".