221386424 has 32 divisors (see below), whose sum is σ = 478846080. Its totient is φ = 93990624.

The previous prime is 221386411. The next prime is 221386441. The reversal of 221386424 is 424683122.

221386424 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

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, 12482 + ... + 24465.

It is an arithmetic number, because the mean of its divisors is an integer number (14963940).

Almost surely, 2^221386424 is an apocalyptic number.

It is an amenable number.

221386424 is an abundant number, since it is smaller than the sum of its proper divisors (257459656).

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

221386424 is a wasteful number, since it uses less digits than its factorization.

221386424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37067 (or 37063 counting only the distinct ones).

The product of its digits is 18432, while the sum is 32.

The square root of 221386424 is about 14879.0599165404. The cubic root of 221386424 is about 604.9465371786.

The spelling of 221386424 in words is "two hundred twenty-one million, three hundred eighty-six thousand, four hundred twenty-four".