221243550 has 48 divisors (see below), whose sum is σ = 598568832. Its totient is φ = 53634400.

The previous prime is 221243549. The next prime is 221243563. The reversal of 221243550 is 55342122.

It is a self number, because there is not a number n which added to its sum of digits gives 221243550.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65394 + ... + 68693.

It is an arithmetic number, because the mean of its divisors is an integer number (12470184).

Almost surely, 2^221243550 is an apocalyptic number.

221243550 is an abundant number, since it is smaller than the sum of its proper divisors (377325282).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221243550 is a wasteful number, since it uses less digits than its factorization.

221243550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134113 (or 134108 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 221243550 is about 14874.2579646852. The cubic root of 221243550 is about 604.8163730223.

Adding to 221243550 its reverse (55342122), we get a palindrome (276585672).

The spelling of 221243550 in words is "two hundred twenty-one million, two hundred forty-three thousand, five hundred fifty".