22418021 has 4 divisors (see below), whose sum is σ = 22964844. Its totient is φ = 21871200.

The previous prime is 22418017. The next prime is 22418047. The reversal of 22418021 is 12081422.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12081422 = 2 ⋅6040711.

It can be written as a sum of positive squares in 2 ways, for example, as 7317025 + 15100996 = 2705^2 + 3886^2 .

It is a cyclic number.

It is not a de Polignac number, because 22418021 - 2² = 22418017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22417984 and 22418002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22418821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273350 + ... + 273431.

It is an arithmetic number, because the mean of its divisors is an integer number (5741211).

Almost surely, 2^22418021 is an apocalyptic number.

It is an amenable number.

22418021 is a deficient number, since it is larger than the sum of its proper divisors (546823).

22418021 is an equidigital number, since it uses as much as digits as its factorization.

22418021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546822.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 22418021 is about 4734.7672593275. The cubic root of 22418021 is about 281.9675238828.

Adding to 22418021 its reverse (12081422), we get a palindrome (34499443).

The spelling of 22418021 in words is "twenty-two million, four hundred eighteen thousand, twenty-one".