225221918 has 4 divisors (see below), whose sum is σ = 337832880. Its totient is φ = 112610958.

The previous prime is 225221903. The next prime is 225221947. The reversal of 225221918 is 819122522.

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: 819122522 = 2 ⋅409561261.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 56305478 + ... + 56305481.

It is an arithmetic number, because the mean of its divisors is an integer number (84458220).

Almost surely, 2^225221918 is an apocalyptic number.

225221918 is a deficient number, since it is larger than the sum of its proper divisors (112610962).

225221918 is a wasteful number, since it uses less digits than its factorization.

225221918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112610961.

The product of its digits is 5760, while the sum is 32.

The square root of 225221918 is about 15007.3954435805. The cubic root of 225221918 is about 608.4200968302.

The spelling of 225221918 in words is "two hundred twenty-five million, two hundred twenty-one thousand, nine hundred eighteen".