221021200 has 30 divisors (see below), whose sum is σ = 531004394. Its totient is φ = 88408320.

The previous prime is 221021197. The next prime is 221021221. The reversal of 221021200 is 2120122.

It can be written as a sum of positive squares in 3 ways, for example, as 4460544 + 216560656 = 2112^2 + 14716^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

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, 275877 + ... + 276676.

Almost surely, 2^221021200 is an apocalyptic number.

221021200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021200 is an abundant number, since it is smaller than the sum of its proper divisors (309983194).

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

221021200 is a wasteful number, since it uses less digits than its factorization.

221021200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552571 (or 552560 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 221021200 is about 14866.7817633811. The cubic root of 221021200 is about 604.6136914121.

Adding to 221021200 its reverse (2120122), we get a palindrome (223141322).

The spelling of 221021200 in words is "two hundred twenty-one million, twenty-one thousand, two hundred".