221388550 has 12 divisors (see below), whose sum is σ = 411782796. Its totient is φ = 88555400.

The previous prime is 221388533. The next prime is 221388611. The reversal of 221388550 is 55883122.

It is a super-2 number, since 2×221388550² = 98025780142205000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2213836 + ... + 2213935.

It is an arithmetic number, because the mean of its divisors is an integer number (34315233).

Almost surely, 2^221388550 is an apocalyptic number.

221388550 is a deficient number, since it is larger than the sum of its proper divisors (190394246).

221388550 is a wasteful number, since it uses less digits than its factorization.

221388550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4427783 (or 4427778 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 221388550 is about 14879.1313590545. The cubic root of 221388550 is about 604.9484736301.

The spelling of 221388550 in words is "two hundred twenty-one million, three hundred eighty-eight thousand, five hundred fifty".