22218425 has 6 divisors (see below), whose sum is σ = 27550878. Its totient is φ = 17774720.

The previous prime is 22218419. The next prime is 22218509. The reversal of 22218425 is 52481222.

It can be written as a sum of positive squares in 3 ways, for example, as 241081 + 21977344 = 491^2 + 4688^2 .

It is not a de Polignac number, because 22218425 - 2⁴ = 22218409 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22218394 and 22218403.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 444344 + ... + 444393.

It is an arithmetic number, because the mean of its divisors is an integer number (4591813).

Almost surely, 2^22218425 is an apocalyptic number.

22218425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

22218425 is a deficient number, since it is larger than the sum of its proper divisors (5332453).

22218425 is an equidigital number, since it uses as much as digits as its factorization.

22218425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888747 (or 888742 counting only the distinct ones).

The product of its digits is 2560, while the sum is 26.

The square root of 22218425 is about 4713.6424344662. The cubic root of 22218425 is about 281.1282073488.

Adding to 22218425 its reverse (52481222), we get a palindrome (74699647).

The spelling of 22218425 in words is "twenty-two million, two hundred eighteen thousand, four hundred twenty-five".