221281000 has 32 divisors (see below), whose sum is σ = 517799880. Its totient is φ = 88512000.

The previous prime is 221280971. The next prime is 221281019. The reversal of 221281000 is 182122.

221281000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 21511044 + 199769956 = 4638^2 + 14134^2 .

It is a super-2 number, since 2×221281000² = 97930561922000000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109641 + ... + 111640.

Almost surely, 2^221281000 is an apocalyptic number.

221281000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221281000 is an abundant number, since it is smaller than the sum of its proper divisors (296518880).

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

221281000 is a wasteful number, since it uses less digits than its factorization.

221281000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221302 (or 221288 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 221281000 is about 14875.5167977452. The cubic root of 221281000 is about 604.8504969478.

The spelling of 221281000 in words is "two hundred twenty-one million, two hundred eighty-one thousand".