221021984 has 24 divisors (see below), whose sum is σ = 458040240. Its totient is φ = 104694336.

The previous prime is 221021951. The next prime is 221021987. The reversal of 221021984 is 489120122.

It is a super-2 number, since 2×221021984² = 97701434822592512, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221021987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181154 + ... + 182369.

It is an arithmetic number, because the mean of its divisors is an integer number (19085010).

Almost surely, 2^221021984 is an apocalyptic number.

It is an amenable number.

221021984 is an abundant number, since it is smaller than the sum of its proper divisors (237018256).

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

221021984 is a wasteful number, since it uses less digits than its factorization.

221021984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363552 (or 363544 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 221021984 is about 14866.8081308666. The cubic root of 221021984 is about 604.6144063007.

The spelling of 221021984 in words is "two hundred twenty-one million, twenty-one thousand, nine hundred eighty-four".