221285018 has 4 divisors (see below), whose sum is σ = 331927530. Its totient is φ = 110642508.

The previous prime is 221285011. The next prime is 221285059. The reversal of 221285018 is 810582122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 116488849 + 104796169 = 10793^2 + 10237^2 .

It is not an unprimeable number, because it can be changed into a prime (221285011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55321253 + ... + 55321256.

Almost surely, 2^221285018 is an apocalyptic number.

221285018 is a deficient number, since it is larger than the sum of its proper divisors (110642512).

221285018 is a wasteful number, since it uses less digits than its factorization.

221285018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110642511.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 221285018 is about 14875.6518512635. The cubic root of 221285018 is about 604.8541578655.

The spelling of 221285018 in words is "two hundred twenty-one million, two hundred eighty-five thousand, eighteen".