221941920 has 96 divisors (see below), whose sum is σ = 715442112. Its totient is φ = 57802752.

The previous prime is 221941913. The next prime is 221941957. The reversal of 221941920 is 29149122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 15264 + ... + 26016.

It is an arithmetic number, because the mean of its divisors is an integer number (7452522).

Almost surely, 2^221941920 is an apocalyptic number.

221941920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221941920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (357721056).

221941920 is an abundant number, since it is smaller than the sum of its proper divisors (493500192).

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

221941920 is a wasteful number, since it uses less digits than its factorization.

221941920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10814 (or 10806 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 221941920 is about 14897.7152610728. The cubic root of 221941920 is about 605.4520856547.

The spelling of 221941920 in words is "two hundred twenty-one million, nine hundred forty-one thousand, nine hundred twenty".