221943920 has 40 divisors (see below), whose sum is σ = 562932720. Its totient is φ = 80706560.

The previous prime is 221943901. The next prime is 221943923. The reversal of 221943920 is 29349122.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221943923) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 125225 + ... + 126984.

It is an arithmetic number, because the mean of its divisors is an integer number (14073318).

Almost surely, 2^221943920 is an apocalyptic number.

221943920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221943920 is an abundant number, since it is smaller than the sum of its proper divisors (340988800).

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

221943920 is a wasteful number, since it uses less digits than its factorization.

221943920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252233 (or 252227 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 221943920 is about 14897.7823853082. The cubic root of 221943920 is about 605.4539042995.

The spelling of 221943920 in words is "two hundred twenty-one million, nine hundred forty-three thousand, nine hundred twenty".